Form 8-K

8-K — AMEREN CORP

Accession: 0001104659-26-078757

Filed: 2026-06-29

Period: 2026-06-29

CIK: 0001002910

SIC: 4931 (ELECTRIC & OTHER SERVICES COMBINED)

Item: Other Events

Item: Financial Statements and Exhibits

Documents

8-K — tm2619063d1_8k.htm (Primary)

EX-1 — EXHIBIT 1.1 (tm2619063d1_ex1.htm)

EX-4.2 — EXHIBIT 4.2 (tm2619063d1_ex4-2.htm)

EX-5.1 — EXHIBIT 5.1 (tm2619063d1_ex5-1.htm)

EX-5.2 — EXHIBIT 5.2 (tm2619063d1_ex5-2.htm)

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of

the

Securities Exchange Act of 1934

Date of report (Date of earliest event reported): June 29, 2026

Commission File Number

Exact

Name of Registrant as

Specified in Charter;

State of Incorporation;

Address and Telephone Number

IRS Employer

Identification Number

1-14756

Ameren

Corporation

(Missouri

Corporation)

1901

Chouteau Avenue

St.

Louis, Missouri

63103

(314)

621-3222

43-1723446

1-2967

Union Electric Company

(Missouri Corporation)

1901 Chouteau Avenue

St. Louis, Missouri 63103

(314)

621-3222

43-0559760

Check

the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrants

under any of the following provisions:

¨ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

¨ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

¨ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

¨ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered

pursuant to Section 12(b) of the Act:

Title

of each class

Trading

Symbol(s)

Name

of each exchange on which registered

Common

Stock, $0.01 par value per share

AEE

New

York Stock Exchange

Indicate by check mark whether the registrant

is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2

of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company

Ameren Corporation

Union Electric Company

an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying

with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.

Ameren Corporation

Union Electric Company

Co-Registrant

CIK

0000100826

Co-Registrant

Amendment Flag

false

Co-Registrant

Form Type

8-K

Co-Registrant

DocumentperiodEndDate

2026-02-27

Co-Registrant

Written Commuunications

false

Co-Registrant

Solicitating Materials

false

Co-Registrant

PreCommencement Tender Offer

false

Co-Registrant

PreCommencement Tender Offer

false

Co-Registrant

Entity PreCommencement Issuer Tender Offer

false

ITEM 8.01 Other Events.

On June 29, 2026, Union Electric Company, doing

business as Ameren Missouri (“Ameren Missouri”), a subsidiary of Ameren Corporation, sold $500 million principal amount of

its 5.75% First Mortgage Bonds due 2056 (the “Bonds”). The Bonds were offered pursuant to a Registration Statement on Form

S-3 (File No. 333-274977-02), which became effective on October 13, 2023, and a Prospectus Supplement dated June 15, 2026, to a Prospectus

dated October 13, 2023. Ameren Missouri received net offering proceeds of approximately $492.2 million, before expenses, upon closing

of the transaction.

This Current Report on Form 8-K is being filed

to report as exhibits certain documents in connection with the offering of the Bonds.

ITEM 9.01 Financial Statements and Exhibits.

(d) Exhibits

Exhibit Number Title

1 Underwriting

Agreement relating to the Bonds, dated June 15,

2026, between Ameren Missouri and the several underwriters named therein, for whom Fifth

Third Securities, Inc., Mizuho Securities USA LLC, TD Securities (USA) LLC, Truist Securities,

Inc. and U.S. Bancorp Investments, Inc. are acting as representatives.

4.1* Indenture

of Mortgage and Deed of Trust, dated June 15, 1937, from Ameren Missouri to The Bank of New

York Mellon, as successor trustee, as amended May 1, 1941, and Second Supplemental Indenture

dated May 1, 1941 (Exhibit B-1, File No. 2-4940).

4.2 Supplemental

Indenture, dated June 1, 2026, by and between Ameren Missouri and The Bank of New York Mellon,

as successor trustee, relating to the 5.75% First Mortgage Bonds due 2056.

5.1 Opinion

of David M. Feinberg, Esq., Executive Vice President, General Counsel and Secretary of Ameren

Missouri, regarding the legality of the Bonds (including consent).

5.2 Opinion

of Morgan, Lewis & Bockius LLP regarding the legality of the Bonds (including consent).

104 Cover

Page Interactive Data File (formatted as Inline XBRL).

Incorporated by reference as indicated.

This

combined Form 8-K is being filed separately by Ameren Corporation and Union Electric Company (each a “registrant”). Information

contained herein relating to any individual registrant has been filed by such registrant on its own behalf. No registrant makes

any representation as to information relating to any other registrant.

- 2 -

SIGNATURES

Pursuant to the requirements of the Securities

Exchange Act of 1934, each registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

The signature for each undersigned company shall be deemed to relate only to matters having reference to such company or its subsidiaries.

AMEREN CORPORATION

(Registrant)

By:

/s/

Leonard P. Singh

Name:

Leonard P. Singh

Title:

Executive Vice President and Chief Financial Officer

UNION ELECTRIC COMPANY

(Registrant)

By:

/s/ Aaron P. Melda

Name:

Aaron P. Melda

Title:

Chairman and President

Date:

June 29, 2026

- 3 -

EX-1 — EXHIBIT 1.1

EX-1

Filename: tm2619063d1_ex1.htm · Sequence: 2

Exhibit 1

Union Electric Company

First Mortgage Bonds due 2056

Underwriting Agreement

June 15, 2026

Fifth Third Securities, Inc.

Mizuho Securities USA LLC

TD Securities (USA) LLC

Truist Securities, Inc.

U.S. Bancorp Investments, Inc.

As Representatives of the several Underwriters

named in Schedule I to the applicable Pricing

Agreement

c/o Fifth Third Securities, Inc.

38 Fountain Square Plaza

Cincinnati, Ohio 45263

Mizuho Securities USA LLC

1271 Avenue of the Americas

New York, New York 10020

TD Securities (USA) LLC

1 Vanderbilt Avenue, 11th Floor

New York, New York 10017

Truist Securities, Inc.

50 Hudson Yards, 70th Floor

New York, New York 10001

U.S. Bancorp Investments, Inc.

214 North Tryon Street, 26th Floor

Charlotte, North Carolina 28202

Ladies and Gentlemen:

From time to time, Union

Electric Company, a Missouri corporation (the “Company”), proposes to enter into one or more Pricing Agreements (each,

a “Pricing Agreement”) in the form of Annex I hereto, with such additions and deletions as the parties thereto may

determine, and, subject to the terms and conditions stated herein and therein, to issue and sell to the firms named in Schedule I to

the applicable Pricing Agreement (such firms constituting the “Underwriters” with respect to such Pricing Agreement

and the securities specified therein) certain of its first mortgage bonds specified in Schedule II to such Pricing Agreement (with respect

to such Pricing Agreement, the “First Mortgage Bonds”).

The terms and rights of any

particular issuance of the First Mortgage Bonds shall be as specified in the Pricing Agreement relating thereto and will be issued under

and pursuant to the Indenture of Mortgage and Deed of Trust, dated June 15, 1937, executed by the Company to The Bank of New York

Mellon, as successor trustee (the “Trustee”), as heretofore amended and supplemented by various supplemental indentures,

and as to be further amended and supplemented by a supplemental indenture relating to the First Mortgage Bonds (with respect to such

Pricing Agreement, the “Supplemental Indenture”). The term “Mortgage,” as used herein, shall be

deemed to refer to such Indenture of Mortgage and Deed of Trust as so amended and supplemented.

1.            Introduction.

Particular sales of the First Mortgage Bonds may be made from time to time to the Underwriters of such First Mortgage Bonds, for whom

the firms designated as representatives of the Underwriters of such First Mortgage Bonds in this Underwriting Agreement or the Pricing

Agreement relating thereto will act as representatives (the “Representatives”). The term “Representatives”

also refers to a single firm acting as sole representative of the Underwriters or to an Underwriter or Underwriters who act without any

firm being designated as its or their representatives. This Underwriting Agreement shall not be construed as an obligation of the Company

to sell any of the First Mortgage Bonds or as an obligation of any of the Underwriters to purchase the First Mortgage Bonds. The obligation

of the Company to issue and sell any of the First Mortgage Bonds and the obligation of any of the Underwriters to purchase any of the

First Mortgage Bonds shall be evidenced by the Pricing Agreement with respect to the First Mortgage Bonds specified therein. Each Pricing

Agreement shall specify the title and aggregate principal amount of such First Mortgage Bonds, the offering price of such First Mortgage

Bonds, the purchase price to the Underwriters of such First Mortgage Bonds, the Supplemental Indenture, the Time of Sale (as defined

herein) and the Time of Sale Information (as defined in the Pricing Agreement relating to the First Mortgage Bonds) with respect to such

First Mortgage Bonds, the names of the Underwriters of such First Mortgage Bonds, the names of the Representatives of such Underwriters,

if any, and the principal amount of such First Mortgage Bonds to be purchased by each Underwriter and shall set forth the Time of Delivery

(as defined herein). The obligations of the Underwriters under this Underwriting Agreement and each Pricing Agreement shall be several

and not joint.

2.            Representations

and Warranties of the Company. The Company represents and warrants to, and agrees with, each of the Underwriters that:

(a)            The

Company meets the requirements for the use of an “automatic shelf registration statement”, as defined in Rule 405 under

the Securities Act of 1933, as amended (the “Act”), and such registration statement on Form S-3 (File No. 333-274977-02)

in respect of the First Mortgage Bonds has been filed with the Securities and Exchange Commission (the “Commission”)

not earlier than three years prior to the date hereof; such registration statement, and any post-effective amendment thereto, became

effective on filing with the Commission; no stop order suspending the effectiveness of such registration statement, any post-effective

amendment thereto or any part thereof has been issued and no proceeding for that purpose or pursuant to Section 8A of the Act against

the Company or relating to the offering of the First Mortgage Bonds has been initiated or threatened by the Commission, and no notice

of objection of the Commission to the use of such registration statement or any post-effective amendment thereto pursuant to Rule 401(g)(2) under

the Act has been received by the Company; any prospectus related to the Company included in such registration statement at the time it

became effective that omits Rule 430 Information (as defined herein) is hereinafter called a “Base Prospectus”;

any preliminary prospectus supplement (together with the accompanying Base Prospectus) used in connection with the offering and sale

of the First Mortgage Bonds that is deemed to be part of and included in such registration statement pursuant to Rule 430B(e) under

the Act, is hereinafter called a “Preliminary Prospectus”; the various parts of such registration statement and any

post-effective amendment thereto, including all exhibits thereto and the documents incorporated by reference in the prospectus contained

in such registration statement at the time each such part of such registration statement became effective, but excluding any Form T-1,

each as amended at the time each such part of such registration statement became effective, and including any information omitted from

such registration statement at the time each such part of such registration statement became effective, but that is deemed to be part

of such registration statement pursuant to Rule 430A, Rule 430B or Rule 430C under the Act at the time set forth therein

(“Rule 430 Information”), are hereinafter collectively called the “Registration Statement”;

the Base Prospectus and prospectus supplement in the form first used (or made available upon request of purchasers pursuant to Rule 173

under the Act) in connection with confirmation of sales of the First Mortgage Bonds and filed by the Company with the Commission pursuant

to Rule 424(b) under the Act in accordance with Section 5(a) hereof is hereinafter called the “Prospectus”;

any reference herein to the Registration Statement, any Preliminary Prospectus or the Prospectus shall be deemed to refer to and include

the documents incorporated by reference therein, as of the effective date of the Registration Statement applicable to the Company and

for the First Mortgage Bonds pursuant to Rule 430B(f)(2) under the Act, the date of such Preliminary Prospectus or the date

of the Prospectus, as the case may be; any reference to any amendment or supplement to the Registration Statement, any Preliminary Prospectus

or the Prospectus shall be deemed to include any documents filed after the effective date of the Registration Statement applicable to

the Company and for the First Mortgage Bonds pursuant to Rule 430B(f)(2) under the Act, the date of such Preliminary Prospectus

or the date of the Prospectus, as the case may be, under the Securities Exchange Act of 1934, as amended (the “Exchange Act”),

and the rules and regulations of the Commission thereunder, and incorporated by reference in the Registration Statement, such Preliminary

Prospectus or the Prospectus, as the case may be; and, at the time set forth in the Pricing Agreement relating to the First Mortgage

Bonds (the “Time of Sale”), the Company had prepared the Time of Sale Information excluding the information provided

by the Underwriters specified in Section 9(b) hereof.

(b)            The

documents incorporated by reference in the Registration Statement, the Prospectus or the Time of Sale Information, when they became effective

or were filed with the Commission, as the case may be, conformed in all material respects to the requirements of the Act or the Exchange

Act, as applicable, and the rules and regulations of the Commission thereunder, and none of such documents, as of such times, contained

any untrue statement of a material fact or omitted to state a material fact required to be stated therein or necessary to make the statements

therein, in the light of the circumstances under which they were made, not misleading; and any further documents so filed and incorporated

by reference in the Registration Statement, the Prospectus or the Time of Sale Information or any further amendment or supplement thereto,

when such documents become effective or are filed with the Commission, as the case may be, will conform in all material respects to the

requirements of the Act or the Exchange Act, as applicable, and the rules and regulations of the Commission thereunder and, as of

such times, will not contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or

necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading.

Registration Statement, the preliminary prospectus supplement dated June 15, 2026 together with the prospectus dated October 13,

2023 (collectively, the “Specified Preliminary Prospectus”) and the Prospectus conform, and any further amendments

or supplements to the Registration Statement, the Specified Preliminary Prospectus or the Prospectus will conform, in all material respects,

to the requirements of the Act and the Trust Indenture Act of 1939, as amended (the “Trust Indenture Act”), and the

rules and regulations of the Commission thereunder. The Registration Statement and any amendment thereto do not and will not, as

of the latest date as of which any part of the Registration Statement relating to the First Mortgage Bonds became, or is deemed to have

become, effective under the Act in accordance with the rules and regulations of the Commission thereunder, contain an untrue statement

of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading,

and the Specified Preliminary Prospectus and the Prospectus and any amendment or supplement thereto, as of their respective dates, and,

as to the Prospectus, as of the Time of Delivery, do not and will not contain an untrue statement of a material fact or omit to state

a material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading;

provided, in each case, however, that this representation and warranty shall not apply to any statements or omissions made in reliance

upon and in conformity with information furnished in writing to the Company by an Underwriter of the First Mortgage Bonds through the

Representatives expressly for use in the Registration Statement, the Specified Preliminary Prospectus or the Prospectus, which information

is specified in Section 9(b) hereof.

(d)            The

Company has been duly incorporated and is validly existing as a corporation and is in good standing under the laws of the State of Missouri,

with corporate power and authority to own or lease its properties and conduct its business as described in the Time of Sale Information

and the Prospectus and to execute, deliver and perform the Company’s obligations under, or as contemplated by, this Underwriting

Agreement and to do all and any of the acts necessary in connection with or arising from the transactions contemplated hereby; and the

Company is duly qualified to do business as a foreign corporation and is in good standing in all other jurisdictions in which its ownership

or lease of property or the conduct of its business requires such qualification, except to the extent that the failure to be so qualified

or to be in good standing would not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect (as defined

herein). The Company has no significant subsidiaries (as defined in Rule 405 under the Act).

(e)            The

consolidated financial statements of the Company incorporated by reference in the Registration Statement, the Time of Sale Information

and the Prospectus fairly present the financial condition of the Company as of the dates indicated and the results of the Company’s

operations and cash flows for the periods therein specified and have been prepared in conformity with United States generally accepted

accounting principles applied on a consistent basis throughout the periods involved, except as otherwise indicated therein; and the interactive

data in eXtensible Business Reporting Language filed as exhibits to the periodic reports incorporated by reference in the Registration

Statement, the Time of Sale Information and the Prospectus fairly presents the information called for in all material respects and has

been prepared in accordance with the Commission’s rules and guidelines applicable thereto.

(f)            Neither

the Company nor any of its subsidiaries has sustained, since the date of the latest audited consolidated financial statements incorporated

by reference in the Time of Sale Information and the Prospectus, any material loss or interference with its business from fire, explosion,

flood or other calamity, whether or not covered by insurance, or from any labor dispute or court or governmental action, order or decree,

other than as set forth or contemplated in the Time of Sale Information and the Prospectus, and since the respective dates as of which

information is given in the Time of Sale Information, (i) the Company has not incurred any liabilities or obligations, direct or

contingent, or entered into any transactions, not in the ordinary course of business, that are material to the Company and (ii) there

has not been any material adverse change, or any development involving a prospective material adverse change, in or affecting the general

affairs, management, financial position, shareholders’ equity or consolidated results of operations of the Company and its subsidiaries,

taken as a whole, in each case, other than as set forth or contemplated in the Time of Sale Information.

(g)            The

Company has an authorized capitalization as disclosed in the Time of Sale Information and the Prospectus, and all of the issued shares

of capital stock of the Company have been duly and validly authorized and issued and are fully paid and non-assessable.

(h)            The

First Mortgage Bonds have been duly authorized by the Company for issuance and sale to the Underwriters, and, when the First Mortgage

Bonds are executed and authenticated in accordance with the provisions of the Mortgage and delivered by the Company in accordance with

this Underwriting Agreement and the Pricing Agreement against payment of the consideration set forth in such Pricing Agreement, such

First Mortgage Bonds will constitute valid and legally binding obligations of the Company enforceable against the Company in accordance

with their terms and the terms of the Mortgage, except as may be limited by the Exceptions (as defined below), and will be entitled to

the benefit of the security afforded by the Mortgage; the Mortgage has been duly authorized by the Company and duly qualified under the

Trust Indenture Act and, at the Time of Delivery, the Mortgage will be duly executed and delivered by the Company and will be a valid

and legally binding agreement of the Company enforceable against the Company in accordance with its terms, subject to the laws of the

States of Missouri, Illinois or Iowa affecting the remedies for the enforcement of the security provided for therein and except

as may be limited by (i) bankruptcy, insolvency, fraudulent conveyance, reorganization, moratorium and other similar laws relating

to or affecting mortgagees’ and other creditors’ rights generally, (ii) general equitable principles (whether considered

in a proceeding in equity or at law) and (iii) concepts of materiality, reasonableness, good faith and fair dealing and the discretion

of the court before which any matter is brought (collectively, the “Exceptions”); and the Mortgage conforms, and the

First Mortgage Bonds will conform, in all material respects, to the descriptions thereof contained in the Time of Sale Information and

the Prospectus.

(i)            Substantially

all of the permanent, fixed properties of the Company are owned in fee simple or are held under valid leases, in each case subject only

to the liens of current mortgages (including the lien of the Mortgage) and “permitted liens” and “judgment liens”

(each as defined in the Mortgage); and such minor imperfections of title and encumbrances, if any, which are not substantial in amount,

do not materially detract from the value or marketability of the properties subject thereto and do not materially impair the title of

the Company to its properties or its right to use its properties in connection with its business as presently conducted; and, based on

the Company’s balance sheet as of March 31, 2026, 6.59% of the Company’s physical property and plant was located in

the States of Illinois or Iowa.

(j)            This

Underwriting Agreement has been, and the Pricing Agreement relating to the First Mortgage Bonds, at the date thereof, will be, duly authorized,

executed and delivered by the Company.

(k)            PricewaterhouseCoopers

LLP, who has audited certain financial statements of the Company and its subsidiaries incorporated by reference in the Registration Statement,

the Time of Sale Information and the Prospectus, is an independent registered public accounting firm with respect to the Company as required

by the Act and the rules and regulations of the Commission thereunder and the Public Company Accounting Oversight Board (United

States).

(l)            The

issuance and sale of the First Mortgage Bonds and the compliance by the Company with all of the provisions of the First Mortgage Bonds,

the Mortgage, this Underwriting Agreement and the Pricing Agreement relating to the First Mortgage Bonds, and the consummation of the

transactions herein and therein contemplated, will not (i) conflict with or result in a breach or violation of any of the terms

or provisions of, or constitute a default under, any indenture, mortgage, deed of trust, loan agreement or other agreement or instrument

to which the Company is a party or by which the Company is bound or to which any of the property or assets of the Company is subject,

(ii) result in any violation of the provisions of the Restated Articles of Incorporation or Bylaws, as amended, of the Company or

(iii) result in any violation of any statute or any order, rule or regulation of any court or governmental agency or body having

jurisdiction over the Company or any of its properties, except, in the case of clauses (i) and (iii) above, for any such conflict,

breach, violation or default that would not, individually or in the aggregate, reasonably be expected to have a Material Adverse Effect.

(m)            The

Missouri Public Service Commission (the “MoPSC”) has issued a final order (the “MoPSC Order”) authorizing

the issuance and sale of the First Mortgage Bonds by the Company in accordance with the terms of the Mortgage; the MoPSC Order is in

full force and effect and not subject to appeal or rehearing and is sufficient to authorize the transactions contemplated by this Underwriting

Agreement and the Pricing Agreement relating to the First Mortgage Bonds to the extent authorization is required; and no other consent,

approval, authorization, order, registration or qualification of or with any court or governmental agency or body, including, without

limitation, any regulatory body of the State of Iowa or the State of Illinois, is required for the issuance and sale of the First Mortgage

Bonds by the Company, or the consummation by the Company of the transactions contemplated by this Underwriting Agreement or such Pricing

Agreement or the Mortgage, except such as have been, or will have been prior to the Time of Delivery, obtained under the Act and the

Trust Indenture Act and such consents, approvals, authorizations, orders, registrations or qualifications as may be required under state

securities or blue sky laws of any jurisdiction (including any non-U.S. jurisdiction) in connection with the purchase and distribution

of such First Mortgage Bonds by the Underwriters.

(n)            The

statements set forth in the Specified Preliminary Prospectus (together with the information set forth in the Time of Sale Information)

and the Prospectus under the captions “Description of Bonds” and “Description of First Mortgage Bonds and Mortgage

Indenture”, insofar as they purport to constitute a summary of the terms of the First Mortgage Bonds and the Mortgage, and under

the captions “Plan of Distribution” and “Underwriting” (except with respect to the information set forth under

the caption “Underwriting—Selling Restrictions”), insofar as they purport to describe the provisions of the laws and

documents referred to therein, are accurate, complete and fair.

(o)            The

Company is not (i) in violation of its Restated Articles of Incorporation or Bylaws, as amended, (ii) to the best knowledge

of the Company, after due inquiry, other than as disclosed in the Time of Sale Information and the Prospectus, in violation of any law,

ordinance, administrative or governmental rule or regulation applicable to the Company, the violation of which would, individually

or in the aggregate, reasonably be expected to have a material adverse effect on the general affairs, management, financial position,

shareholders’ equity or consolidated results of operations of the Company and its subsidiaries, taken as a whole (a “Material

Adverse Effect”), or of any decree of any court or governmental agency or body having jurisdiction over the Company, or (iii) in

default in the performance or observance of any obligation, agreement, covenant or condition contained in any indenture, mortgage, deed

of trust, loan agreement, lease or other agreement or instrument to which the Company is a party or by which the Company or any of the

Company’s properties may be bound, which default would, individually or in the aggregate, reasonably be expected to have a Material

Adverse Effect.

(p)            Other

than as disclosed in the Time of Sale Information and the Prospectus, there are no legal or governmental proceedings pending to which

the Company is a party or of which any property of the Company is the subject which, if determined adversely to the Company, would, individually

or in the aggregate, reasonably be expected to have a Material Adverse Effect; and, to the Company’s knowledge, no such proceedings

are threatened by governmental authorities or others.

(q)            The

Company is not, and, after giving effect to the offering and sale of the First Mortgage Bonds and the application of the net proceeds

thereof, will not be an “investment company,” or an entity “controlled” by an investment company, as such terms

are defined in the Investment Company Act of 1940, as amended.

(r)            Except

as disclosed in the Time of Sale Information and the Prospectus, or except as would not, individually or in the aggregate, reasonably

be expected to have a Material Adverse Effect, the Company (i) is in compliance with any and all applicable federal, state and local

laws and regulations relating to the protection of human health and safety, the environment or hazardous or toxic substances or wastes,

pollutants or contaminants (“Environmental Laws”), (ii) has received all permits, licenses or other approvals

required of the Company under applicable Environmental Laws to conduct the Company’s business and (iii) is in compliance with

all terms and conditions of any such permit, license or approval.

(s)            The

Time of Sale Information at the Time of Sale did not, and at the Time of Delivery will not, contain any untrue statement of a material

fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which

they were made, not misleading; provided that the Company makes no representation and warranty with respect to any statements or omissions

made in reliance upon and in conformity with information furnished in writing to the Company by an Underwriter of the First Mortgage

Bonds through the Representatives expressly for use in such Time of Sale Information, which information is specified in Section 9(b) hereof;

and no statement of material fact that will be included in the Prospectus has been omitted from the Time of Sale Information and no statement

of material fact included in the Time of Sale Information that is required to be included in the Prospectus will be omitted therefrom.

(t)            Other

than the Registration Statement, any Preliminary Prospectus and the Prospectus, the Company (including its agents and representatives,

other than the Underwriters in their capacity as such) has not made, used, prepared, authorized, approved or referred to and will not

prepare, make, use, authorize, approve or refer to any “written communication” (as defined in Rule 405 under the Act)

that constitutes an offer to sell or solicitation of an offer to buy the First Mortgage Bonds (each such communication by the Company

or its agents and representatives (other than a communication referred to in clause (i) below), an “Issuer Free Writing

Prospectus”) other than (i) any document not constituting a prospectus pursuant to Section 2(a)(10)(a) of the

Act or Rule 134 under the Act or (ii) the documents listed on Annex II hereto and other written communications approved in

writing in advance by the Representatives; each such Issuer Free Writing Prospectus complied in all material respects with the Act, has

been filed in accordance with the Act (to the extent required thereby) and, when taken together with the Time of Sale Information at

the Time of Sale, did not, and at the Time of Delivery will not, contain any untrue statement of a material fact or omit to state a material

fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading;

provided that the Company makes no representation and warranty with respect to any statements or omissions made in each such Issuer Free

Writing Prospectus in reliance upon and in conformity with information furnished in writing to the Company by an Underwriter of the First

Mortgage Bonds through the Representatives expressly for use in any Issuer Free Writing Prospectus, which information is specified in

Section 9(b) hereof; and each Issuer Free Writing Prospectus listed on Part B of Annex II hereto does not conflict with

the information contained in the Registration Statement, the Time of Sale Information or the Prospectus.

(u)            (A) (i) At

the time of the initial filing of the Registration Statement, (ii) at the time of the most recent amendment thereto for the purposes

of complying with Section 10(a)(3) of the Act (whether such amendment was by post-effective amendment, incorporated report

filed pursuant to Section 13 or 15(d) of the Exchange Act or form of prospectus), and (iii) at the time the Company or

any person acting on its behalf (within the meaning, for this clause only, of Rule 163(c) under the Act) made any offer relating

to the First Mortgage Bonds in reliance on the exemption of Rule 163 under the Act, the Company was a “well-known seasoned

issuer” within the meaning of subparagraph (1)(ii) of the definition of “well-known seasoned issuer” in Rule 405

under the Act; and (B) at the earliest time after the filing of the Registration Statement that the Company or another offering

participant made a bona fide offer (within the meaning of Rule 164(h)(2) under the Act) of the First Mortgage Bonds, the Company

was not an “ineligible issuer” as defined in Rule 405 under the Act.

(v)            The

Company maintains a system of internal control over financial reporting (as such term is defined in Rule 13a-15(f) under the

Exchange Act) that complies with the requirements of the Exchange Act and has been designed by the Company’s principal executive

officer and principal financial officer, or under their supervision, to provide reasonable assurance that (i) transactions are executed

in accordance with management’s general or specific authorizations; (ii) transactions are recorded as necessary to permit

preparation of financial statements in conformity with generally accepted accounting principles and to maintain asset accountability;

(iii) access to assets is permitted only in accordance with management’s general or specific authorization; and (iv) the

recorded accountability for assets is compared with the existing assets at reasonable intervals and appropriate action is taken with

respect to any differences; and, except as disclosed in the Time of Sale Information and the Prospectus, the Company’s internal

control over financial reporting as of March 31, 2026 was effective and the Company is not aware of any material weaknesses in the

Company’s internal control over financial reporting since that date.

(w)            Except

as disclosed in the Time of Sale Information and the Prospectus, since the date of the latest audited financial statements incorporated

by reference in the Time of Sale Information and the Prospectus, to the knowledge of the Chief Accounting Officer of Ameren Corporation,

there has been no change in the Company’s internal control over financial reporting that has materially affected, or is reasonably

likely to materially affect, the Company’s internal control over financial reporting.

(x)            The

Company maintains disclosure controls and procedures (as such term is defined in Rule 13a-15(e) under the Exchange Act) that

comply with the requirements of the Exchange Act; such disclosure controls and procedures have been designed to ensure that material

information relating to the Company and its subsidiaries is made known to the Company’s principal executive officer and principal

financial officer by others within those entities; such disclosure controls and procedures as of March 31, 2026 were effective;

and, since the date of the latest audited consolidated financial statements incorporated by reference in the Time of Sale Information

and the Prospectus, to the knowledge of the Chief Accounting Officer of Ameren Corporation, there has been no change in the Company’s

disclosure controls and procedures that has materially affected, or is reasonably likely to materially affect, the Company’s disclosure

controls and procedures.

(y)            Ameren

Corporation maintains policies and procedures designed to ensure compliance by, among others, the Company, the Company’s subsidiaries

and their respective directors, officers, employees and agents with all laws, rules and regulations of any jurisdiction applicable

to the Company or its subsidiaries from time to time concerning or relating to bribery, corruption or money laundering (collectively,

“Anti-Corruption Laws”) and applicable economic or financial sanctions or trade embargoes imposed, administered or

enforced from time to time by the U.S. government, including those administrated by the Office of Foreign Assets Control of the U.S.

Department of the Treasury (“OFAC”) or the U.S. Department of State (the “State Department”), or

by the United Nations Security Council (the “UNSC”), the European Union (the “EU”) or His Majesty’s

Treasury of the United Kingdom (collectively, “Sanctions”), and the Company and its subsidiaries and, to the knowledge

of the Company, their respective officers, employees, directors and agents, are in compliance with Anti-Corruption Laws and applicable

Sanctions; and none of (A) the Company, any of its subsidiaries, or, to the knowledge of the Company, any of their respective directors,

officers or employees, or (B) to the knowledge of the Company, any agent of the Company or any of its subsidiaries that will act

in any capacity in connection with, or benefit from, this Underwriting Agreement, is (i) a person listed in any Sanctions-related

list of designated persons maintained by OFAC or the State Department, or by the UNSC, the EU or any EU member state, (ii) a person

operating, organized or resident in a country or territory that is itself the subject or target of any Sanctions (as of the date hereof,

including, without limitation, Crimea, Cuba, Iran, North Korea, the so-called Donetsk People’s Republic, the so-called Luhansk

People’s Republic, the non-government controlled areas of Zaporizhzhia and Kherson or any other Covered Region of Ukraine identified

pursuant to Executive Order 14065) or (iii) any person 50% or more owned or controlled by any such person or persons.

(z)            The

Company will not, directly or indirectly, use the proceeds of the offering of the First Mortgage Bonds, or lend, contribute or otherwise

make available such proceeds to any subsidiary, joint venture partner or other person or entity to fund any activities of or business

with any person or entity that, at the time of such funding, is the subject of Sanctions.

(aa)            Except

as disclosed in the Time of Sale Information and the Prospectus or except as would not, individually or in the aggregate, reasonably

be expected to have a Material Adverse Effect, to the Company’s knowledge there has been no security breach, unauthorized access

or other compromise or misuse of or relating to any of the Company’s information technology and computer systems, networks, hardware,

software, data (including the data of their respective customers, employees, suppliers and vendors and any third party data maintained

by or on behalf of them), equipment or technology (collectively, “IT Systems and Data”). Except as disclosed

in the Time of Sale Information and the Prospectus or except as would not, individually or in the aggregate, reasonably be expected to

have a Material Adverse Effect, the Company has not been notified of, and has no knowledge of any event or condition that would reasonably

be expected to result in, any security breach or other compromise to its IT Systems and Data. The Company has implemented backup

and disaster recovery technology consistent with industry standards and practices. The Company has policies and procedures in place

designed to ensure the integrity and security of its IT Systems and Data and comply with such policies and procedures in all material

respects.

3.            Offering.

Upon the execution of the Pricing Agreement relating to the First Mortgage Bonds, the several Underwriters propose to offer such First

Mortgage Bonds for sale upon the terms and conditions set forth in the Time of Sale Information and the Prospectus.

4.            Payment

and Delivery of Securities. The First Mortgage Bonds to be purchased by each Underwriter pursuant to the Pricing Agreement relating

thereto, in the form specified in such Pricing Agreement, and in such authorized denominations and registered in such names as the Representatives

may request, shall be delivered by or on behalf of the Company to the Representatives for the account of such Underwriter, against payment

by or on behalf of such Underwriter of the purchase price therefor by wire transfer of Federal (same-day) funds to the account specified

by the Company to the Representatives at least twenty-four hours prior to the Time of Delivery. The time and date of such delivery and

payment shall be as specified in Schedule II to the Pricing Agreement relating to the First Mortgage Bonds or at such other time

and date as the Representatives and the Company may agree upon in writing, such time and date being herein called the “Time

of Delivery” for such First Mortgage Bonds.

5.            Covenants

of the Company. The Company agrees with each of the Underwriters:

(a)            To

prepare the Prospectus in a form approved by the Representatives and to file such Prospectus pursuant to Rule 424(b) under

the Act not later than the Commission’s close of business on the second business day following the execution and delivery of the

Pricing Agreement relating to the First Mortgage Bonds or, if applicable, such earlier time as may be required by Rule 424(b) under

the Act; to prepare a final term sheet in substantially the form attached as Schedule III to the applicable Pricing Agreement relating

to such First Mortgage Bonds, and approved by the Representatives, and to file such final term sheet pursuant to Rule 433(d) under

the Act within the time required by such rule; to file promptly all other material required to be filed by the Company with the Commission

pursuant to Rule 433(d) under the Act; to make no further amendment or supplement (except for such final term sheet) to the

Registration Statement or the Prospectus after the date of the Pricing Agreement relating to such First Mortgage Bonds and prior to the

Time of Delivery for such First Mortgage Bonds which shall be disapproved by the Representatives for such First Mortgage Bonds promptly

after reasonable notice thereof; to advise the Representatives promptly of any such amendment or supplement or any amendment or supplement

to any Issuer Free Writing Prospectus after such Time of Delivery and furnish the Representatives with copies thereof; before using,

authorizing, approving, referring to or filing any Issuer Free Writing Prospectus, to furnish to the Representatives and counsel for

the Underwriters a copy of the proposed Issuer Free Writing Prospectus for review and not to use, authorize, approve, refer to or file

any such Issuer Free Writing Prospectus disapproved by the Representatives; to promptly notify the Representatives of any notice given

to the Company by any of Moody’s Investors Service, Inc. or S&P Global Ratings, a division of S&P Global Inc. (each,

a “Rating Agency”), of any intended decrease in any rating of any securities of the Company or of any intended change

in any such rating that does not indicate the direction of the possible change of any such rating, in each case by any such Rating Agency;

to file promptly all reports and any definitive proxy or information statements required to be filed by the Company with the Commission

pursuant to Section 13(a), 13(c), 14 or 15(d) of the Exchange Act subsequent to the date of the Prospectus and for so long

as the delivery of a prospectus (or in lieu thereof, the notice referred to in Rule 173(a) under the Act) is required in connection

with the offering or sale of the First Mortgage Bonds, and during such same period to advise the Representatives, promptly after it receives

notice thereof, of the time when any amendment to the Registration Statement has been filed or becomes effective or any supplement to

the Prospectus or any amended Prospectus has been filed with the Commission, of the issuance by the Commission of any stop order or of

any order preventing or suspending the use of any prospectus relating to the First Mortgage Bonds, of any notice of objection of the

Commission to the use of the Registration Statement or any post-effective amendment thereto pursuant to Rule 401(g)(2) under

the Act, of the suspension of the qualification of such First Mortgage Bonds for offering or sale in any jurisdiction, of the initiation

or threatening of any proceeding for any such purpose or pursuant to Section 8A of the Act against the Company or relating to the

offering of the First Mortgage Bonds, or of any request by the Commission for the amending or supplementing of the Registration Statement

or the Prospectus or for additional information; and, in the event of the issuance of any such stop order or of any such order preventing

or suspending the use of any prospectus relating to the First Mortgage Bonds or suspending any such qualification, to promptly use its

best efforts to obtain the withdrawal of such order.

(b)            If

required by Rule 430B(h) under the Act in connection with the offer and sale of the First Mortgage Bonds, to prepare a prospectus

in a form approved by the Representatives and to file such prospectus pursuant to Rule 424(b) under the Act not later than

may be required by Rule 424 under the Act; and to make no further amendment or supplement to such prospectus which shall be disapproved

by the Representatives promptly after reasonable notice thereof.

from time to time, to take such action as the Representatives may reasonably request to qualify the First Mortgage Bonds for offering

and sale under the securities laws of such jurisdictions as the Representatives may request and to comply with such laws so as to permit

the continuance of sales and dealings therein in such jurisdictions for as long as may be necessary to complete the distribution of such

First Mortgage Bonds, provided that in connection therewith the Company shall not be required to qualify as a foreign corporation or

to file a general consent to service of process in any jurisdiction.

(d)            To

promptly furnish the Underwriters with electronic copies of the Prospectus and each Issuer Free Writing Prospectus prepared by the Company

(to the extent not previously delivered), as amended or supplemented, and, if the delivery of a prospectus (or in lieu thereof, the notice

referred to in Rule 173(a) under the Act) is required at any time in connection with the offering or sale of the First Mortgage

Bonds and if at such time any event shall have occurred as a result of which the Prospectus, the Time of Sale Information or any Issuer

Free Writing Prospectus, as then amended or supplemented, would include an untrue statement of a material fact or omit to state a material

fact necessary in order to make the statements therein, in the light of the circumstances under which they were made when such Prospectus

(or in lieu thereof, the notice referred to in Rule 173(a) under the Act), such Time of Sale Information or such Issuer Free

Writing Prospectus, as then amended or supplemented, is delivered, not misleading, or, if for any other reason it shall be necessary

during such same period to amend or supplement the Prospectus or to file under the Exchange Act any document incorporated by reference

in the Prospectus in order to comply with the Act, the Exchange Act or the Trust Indenture Act, to notify the Representatives and, upon

their request, to file such document and to prepare and furnish without charge to each Underwriter and to any dealer in securities as

many electronic copies as the Representatives may from time to time reasonably request of an amended Prospectus or a supplement to the

Prospectus which will correct such statement or omission or effect such compliance, or, if at any time prior to the Time of Delivery

(i) any event shall occur or condition shall exist as a result of which the Time of Sale Information, as then amended or supplemented,

would include an untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein,

in the light of the circumstances under which they were made, not misleading or (ii) it is necessary to amend or supplement the

Time of Sale Information to comply with law, the Company will immediately notify the Representatives thereof and forthwith prepare and,

subject to Section 5(a) hereof, file with the Commission (to the extent required) and furnish to the Underwriters and to such

dealers as the Representatives may designate, such amendments or supplements to the Time of Sale Information as may be necessary so that

the statements in the Time of Sale Information, as so amended or supplemented, will not include an untrue statement of a material fact

or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they

were made, not misleading or so that the Time of Sale Information will comply with law; and in case any Underwriter is required to deliver

a prospectus (or in lieu thereof, the notice referred to in Rule 173(a) under the Act) in connection with sales of the First

Mortgage Bonds at any time nine months or more after the time of issue of the Prospectus, upon the Representatives’ request, to

prepare and deliver to such Underwriter as many electronic copies as the Representatives may request of an amended or supplemented Prospectus

complying with Section 10(a)(3) of the Act.

(e)            In

accordance with Rule 158 under the Act, to make generally available to its security holders and to holders of the First Mortgage

Bonds, as soon as practicable, but in any event not later than 18 months after the effective date of the Registration Statement (as defined

in Rule 158(c) under the Act), an earning statement of the Company (which need not be audited) complying with Section 11(a) of

the Act and the rules and regulations of the Commission thereunder (including, at the option of the Company, Rule 158 under

the Act).

(f)            During

the period beginning from the date of the Pricing Agreement for the First Mortgage Bonds and continuing to and including the Time of

Delivery for such First Mortgage Bonds, not to offer, sell, contract to sell, pledge, grant any option to purchase, make any short sale

or otherwise dispose of any debt securities of the Company which mature more than one year after such Time of Delivery and which are

substantially similar to such First Mortgage Bonds, without the prior written consent of the Representatives.

(g)            Upon

request of an Underwriter, to furnish, or cause to be furnished, to such Underwriter an electronic version of the Company’s trademarks,

service marks and corporate logo for use on the website, if any, operated by such Underwriter for the purpose of facilitating the on-line

offering of the First Mortgage Bonds (the “License”); provided, however, that the License shall be used solely for

the purpose described in this Section 5(g), is granted without any fee and may not be assigned or transferred.

(h)            To

apply the net proceeds from the sale of the First Mortgage Bonds for the purposes set forth in the Registration Statement, the Time of

Sale Information and the Prospectus.

(i)            Pursuant

to reasonable procedures developed in good faith, to retain copies of each Issuer Free Writing Prospectus that is not filed with the

Commission in accordance with Rule 433 under the Act.

(j)            If

immediately prior to the third anniversary (the “Renewal Deadline”) of the initial effective date of the Registration

Statement, any of the First Mortgage Bonds remain unsold by the Underwriters, to file, prior to the Renewal Deadline, if it has not already

done so and is eligible to do so, a new automatic shelf registration statement relating to the First Mortgage Bonds, in a form satisfactory

to the Representatives. If the Company is no longer eligible to file an automatic shelf registration statement, the Company will, prior

to the Renewal Deadline, if it has not already done so, file a new shelf registration statement relating to the First Mortgage Bonds,

in a form satisfactory to the Representatives, and will use its best efforts to cause such registration statement to be declared effective

within 60 days after the Renewal Deadline. The Company will take all other action necessary or appropriate to permit the public

offering and sale of the First Mortgage Bonds to continue as contemplated in the expired registration statement relating to the First

Mortgage Bonds. References herein to the Registration Statement shall include such new automatic shelf registration statement or such

new shelf registration statement, as the case may be.

(k)            If

at any time when the First Mortgage Bonds remain unsold by the Underwriters the Company receives from the Commission a notice pursuant

to Rule 401(g)(2) under the Act or otherwise ceases to be eligible to use the automatic shelf registration statement form,

to (i) promptly notify the Representatives, (ii) promptly file a new registration statement or post-effective amendment on

the proper form relating to the First Mortgage Bonds, in a form satisfactory to the Representatives, (iii) use its best efforts

to cause such registration statement or post-effective amendment to be declared effective and (iv) promptly notify the Representatives

of such effectiveness. The Company will take all other action necessary or appropriate to permit the public offering and sale of the

First Mortgage Bonds to continue as contemplated in the registration statement that was the subject of the Rule 401(g)(2) notice

or for which the Company has otherwise become ineligible. References herein to the Registration Statement shall include such new registration

statement or post-effective amendment, as the case may be.

(l)            As

soon as practicable after the Time of Delivery, to make all recordings, registrations and filings necessary to preserve the lien of the

Mortgage and the rights under the Supplemental Indenture.

6.            Payment

of Expenses. Whether or not any sale of the First Mortgage Bonds is consummated, the Company covenants and agrees with the several

Underwriters that the Company will pay or cause to be paid the following: (i) the fees, disbursements and expenses of the Company’s

counsel and accountants in connection with the registration of the First Mortgage Bonds under the Act and all other expenses in connection

with the preparation, printing, reproduction and filing of the Registration Statement, any Preliminary Prospectus, any Issuer Free Writing

Prospectus, the Time of Sale Information and the Prospectus and amendments and supplements thereto and the mailing and delivering of

copies thereof to the Underwriters and any dealers; (ii) the applicable Commission filing fees relating to the First Mortgage Bonds

within the time required by Rule 456(b)(1) under the Act without regard to the proviso thereof; (iii) the cost of printing

or producing any agreement among underwriters, this Underwriting Agreement, any Pricing Agreement, the Mortgage, any blue sky surveys,

closing documents (including any compilations thereof) and any other documents in connection with the offering, purchase, sale and delivery

of the First Mortgage Bonds; (iv) all expenses (not to exceed $5,000) in connection with the qualification of the First Mortgage

Bonds for offering and sale under state securities laws as provided in Section 5(c) hereof, including the fees and disbursements

of counsel for the Underwriters in connection with such qualification and in connection with any blue sky surveys; (v) any fees

charged by securities rating services for rating the First Mortgage Bonds; (vi) any filing fees incident to, and the fees and disbursements

of counsel for the Underwriters in connection with, any required review by the Financial Industry Regulatory Authority of the terms of

the sale of the First Mortgage Bonds; (vii) the cost of preparing certificates for the First Mortgage Bonds; (viii) the fees

and expenses of the Trustee and any agent of the Trustee and the fees and disbursements of counsel for the Trustee in connection with

the Mortgage and the First Mortgage Bonds; and (ix) all other costs and expenses incurred by the Company incident to the performance

of the Company’s obligations hereunder that are not otherwise specifically provided for in this Section 6. It is understood,

however, that, except as provided in this Section 6, and Sections 9 and 12 hereof, the Underwriters will pay all of their own costs

and expenses, including the fees of their counsel, any advertising expenses in connection with any offers the Underwriters may make and

transfer taxes on resale of any of the First Mortgage Bonds by them.

7.            Issuer

Free Writing Prospectuses. Each Underwriter hereby represents and agrees that, except for one or more term sheets containing the

information set forth in Schedule III to the applicable Pricing Agreement, it has not and will not use, authorize use of, refer

to, or participate in the use of, any “free writing prospectus”, as defined in Rule 405 under the Act (which term includes

use of any written information furnished to the Commission by the Company and not incorporated by reference into the Registration Statement

and any press release issued by the Company) other than (i) one or more term sheets relating to the First Mortgage Bonds which are

not Issuer Free Writing Prospectuses and which contain preliminary terms of the First Mortgage Bonds and related customary information

not inconsistent with the final term sheet prepared and filed by the Company pursuant to Section 5(a) hereof, (ii) a free

writing prospectus that contains no “issuer information” (as defined in Rule 433(h)(2) under the Act) that was

not included (including through incorporation by reference) in the Specified Preliminary Prospectus or a previously filed Issuer Free

Writing Prospectus, (iii) any Bloomberg L.P. or other electronic communication regarding comparable bond prices, (iv) any Issuer

Free Writing Prospectus listed on Annex II hereto or prepared pursuant to Section 2(t) or Section 5(a) hereof, or

(v) any free writing prospectus prepared by such Underwriter and approved by the Company in advance in writing.

8.            Conditions

to Underwriters’ Obligations. The obligations of the several Underwriters of the First Mortgage Bonds under the Pricing Agreement

relating to such First Mortgage Bonds shall be subject, in the discretion of the Representatives, to the condition that all representations

and warranties and other statements of the Company contained herein and in or incorporated by reference in the Pricing Agreement relating

to such First Mortgage Bonds are, at and as of the Time of Sale and the Time of Delivery for such First Mortgage Bonds, true and correct,

the condition that the Company shall have performed all of its obligations hereunder theretofore to be performed at and as of the Time

of Sale and the Time of Delivery for such First Mortgage Bonds, as the case may be, and the following additional conditions:

(a)            The

Prospectus shall have been filed with the Commission pursuant to Rule 424(b) under the Act within the applicable time period

prescribed for such filing by the rules and regulations under the Act and in accordance with Section 5(a) hereof; each

Issuer Free Writing Prospectus shall have been timely filed with the Commission under the Act to the extent required by Rule 433

under the Act; no stop order suspending the effectiveness of the Registration Statement or any part thereof shall have been issued and

no proceeding for that purpose or pursuant to Section 8A of the Act against the Company or related to the offering of the First

Mortgage Bonds shall have been initiated or threatened by the Commission and no notice of objection of the Commission to the use of the

Registration Statement or any post-effective amendment thereto pursuant to Rule 401(g)(2) under the Act shall have been received;

no stop order suspending or preventing the use of the Prospectus or any Issuer Free Writing Prospectus shall have been initiated or threatened

by the Commission; and all requests for additional information on the part of the Commission shall have been complied with to the Representatives’

reasonable satisfaction.

(b)            Counsel

for the Underwriters shall have furnished to the Underwriters such written opinion or opinions, dated the Time of Delivery for such First

Mortgage Bonds, with respect to such matters as the Underwriters may reasonably request, and such counsel shall have received such documents

and information as they may reasonably request to enable them to pass upon such matters. In rendering such opinion, such counsel may

(i) state that such opinion is limited to matters covered by the federal laws of the United States of America and (ii) rely

as to matters of fact, to the extent deemed proper, on certificates of responsible officers of the Company and public officials.

Underwriters shall have received the favorable opinions dated the Time of Delivery for such First Mortgage Bonds of:

(i) David M. Feinberg, Esq.,

Executive Vice President, General Counsel and Secretary of the Company, in the form attached as Exhibit A hereto (x) with such

changes therein as may be agreed upon by the Company and the Representatives with the approval of counsel for the Underwriters, and (y) if

the Time of Sale Information shall be supplemented after being furnished to the Underwriters for use in offering the First Mortgage Bonds,

with changes therein to reflect such supplementation; and

(ii) Morgan, Lewis &

Bockius LLP, in the form attached as Exhibit B hereto (x) with such changes therein as may be agreed upon by the Company and

the Representatives with the approval of counsel for the Underwriters, and (y) if the Time of Sale Information shall be supplemented

after being furnished to the Underwriters for use in offering the First Mortgage Bonds, with changes therein to reflect such supplementation.

(d)            On

the date of the Pricing Agreement for such First Mortgage Bonds and at the Time of Delivery for such First Mortgage Bonds, PricewaterhouseCoopers

LLP shall have furnished to the Underwriters a letter, dated the date of such Pricing Agreement, and a letter dated such Time of Delivery,

respectively, in form and substance satisfactory to the Representatives, with respect to the consolidated financial statements of the

Company and its subsidiaries incorporated by reference in the Registration Statement, the Time of Sale Information and the Prospectus.

(e)            (i) Neither

the Company nor any of its subsidiaries shall have sustained, since the date of the latest audited consolidated financial statements

incorporated by reference in the Time of Sale Information, any loss or interference with its business from fire, explosion, flood or

other calamity, whether or not covered by insurance, or from any labor dispute or court or governmental action, order or decree, other

than as disclosed or contemplated in the Time of Sale Information, and (ii) since the respective dates as of which information is

given in the Time of Sale Information, there shall not have been any change, or any development involving a prospective change, in or

affecting the general affairs, management, financial position, shareholders’ equity or consolidated results of operations of the

Company and its subsidiaries, taken as a whole, other than as disclosed or contemplated in the Time of Sale Information, the effect of

which, in any such case described in clause (i) or (ii), is in the judgment of the Representatives so material and adverse as to

make it impracticable or inadvisable to proceed with the public offering, sale or delivery of the First Mortgage Bonds on the terms and

in the manner contemplated in the Time of Sale Information and the Prospectus.

(f)            On

or prior to the Time of Delivery, the Representatives shall have received satisfactory evidence that the First Mortgage Bonds are rated

as set forth in the Issuer Free Writing Prospectus listed on Part A of Annex II hereto and that such ratings are in effect at the

Time of Delivery.

(g)            On

or after the date of the Pricing Agreement relating to the First Mortgage Bonds, (i) no downgrading shall have occurred in the rating

accorded the Company’s debt securities or preferred stock by any Rating Agency, and (ii) no such Rating Agency shall have

publicly announced that it has under surveillance or review, with possible negative implications, its rating of any of the Company’s

debt securities or preferred stock, unless such surveillance or review has been publicly announced prior to the date of the Pricing Agreement.

(h)            On

or after the date of the Pricing Agreement relating to the First Mortgage Bonds there shall not have occurred any of the following: (i) a

suspension or material limitation in trading in securities generally by the Commission, the New York Stock Exchange or The Nasdaq Stock

Market or any setting of minimum or maximum prices for trading thereon; (ii) a suspension or material limitation in trading in the

Company’s securities by the Commission, the New York Stock Exchange, or The Nasdaq Stock Market; (iii) a general moratorium

on commercial banking activities declared by Federal, New York state or Missouri state authorities or a material disruption has occurred

in commercial banking or securities settlement or clearance services in the United States; (iv) any outbreak or escalation of hostilities

involving the United States or the declaration by the United States of a national emergency or war; or (v) the occurrence of any

other calamity or crisis or any change in financial, political or economic conditions in the United States or elsewhere, if the effect

of any event specified in clause (iv) or (v), in the judgment of the Representatives, makes it impracticable or inadvisable to proceed

with the public offering, sale or delivery of the First Mortgage Bonds on the terms and in the manner contemplated in the Time of Sale

Information and the Prospectus.

(i)            The

Company shall have furnished or caused to be furnished to the Representatives at the Time of Delivery for the First Mortgage Bonds a

certificate or certificates of officers of the Company satisfactory to the Representatives as to the accuracy of the representations

and warranties of the Company herein at and as of such Time of Delivery, as to the performance by the Company of all of its obligations

hereunder to be performed at or prior to such Time of Delivery, as to the matters set forth in Section 8(a) and Section 8(e) hereof

and as to such other matters as the Representatives may reasonably request.

(j)            The

MoPSC Order shall be in full force and effect at the Time of Delivery.

If any of the events specified

in Sections 8(e), 8(g) or 8(h) hereof shall have occurred or the representation in Section 2(s) hereof is incorrect,

the Pricing Agreement relating to the First Mortgage Bonds may be terminated by the Representatives on notice to the Company at any time

on or prior to the Time of Delivery and upon such notice being given, the parties hereto and thereto shall be released and discharged

from their respective obligations hereunder and thereunder (except for the liability of the Company pursuant to Sections 6 or 12 hereof

and the obligations of the parties hereto and thereto pursuant to Section 9 hereof). Notwithstanding any such termination, the provisions

of Sections 6, 9, 11, 12, 13, 14, 16, 17 and 20 hereof shall remain in full force and effect.

9.            Indemnification

and Contribution.

(a)            The

Company will indemnify and hold harmless each Underwriter against any losses, claims, damages or liabilities, joint or several, to which

such Underwriter may become subject, under the Act or otherwise, insofar as such losses, claims, damages or liabilities (or actions in

respect thereof) arise out of or are based upon (i) an untrue statement or alleged untrue statement of a material fact contained

in the Registration Statement, or any amendment or supplement thereto, or arise out of or are based upon the omission or alleged omission

to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading, or (ii) any

untrue statement or alleged untrue statement of a material fact contained in the Prospectus (or any amendment or supplement thereto),

any Preliminary Prospectus, any Issuer Free Writing Prospectus, the Time of Sale Information, or any “issuer information”

filed or required to be filed under Rule 433(d) of the Act, or arise out of or are based upon the omission or alleged omission

to state therein a material fact necessary in order to make the statements therein, in the light of the circumstances under which they

were made, not misleading, and will reimburse each Underwriter for any legal or other expenses reasonably incurred by such Underwriter

in connection with investigating or defending any such action or claim as such expenses are incurred; provided, however, that the Company

shall not be liable in any such case to the extent that any such loss, claim, damage or liability arises out of or is based upon an untrue

statement or alleged untrue statement or omission or alleged omission made in the Registration Statement, the Prospectus as amended or

supplemented, any Preliminary Prospectus, any Issuer Free Writing Prospectus or the Time of Sale Information, or any such amendment or

supplement of or to the foregoing, in reliance upon and in conformity with written information furnished to the Company by any Underwriter

of the First Mortgage Bonds through the Representatives expressly for use in the Registration Statement, the Prospectus as amended or

supplemented, any Preliminary Prospectus, any Issuer Free Writing Prospectus or the Time of Sale Information, or any such amendment or

supplement of or to the foregoing, which information is specified in Section 9(b) hereof.

(b)            Each

Underwriter severally and not jointly will indemnify and hold harmless the Company against any losses, claims, damages or liabilities

to which the Company may become subject, under the Act or otherwise, insofar as such losses, claims, damages or liabilities (or actions

in respect thereof) arise out of or are based upon (i) an untrue statement or alleged untrue statement of a material fact contained

in the Registration Statement, or any amendment or supplement thereto, or arise out of or are based upon the omission or alleged omission

to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading, or (ii) any

untrue statement or alleged untrue statement of a material fact contained in the Prospectus (or any amendment or supplement thereto),

any Preliminary Prospectus, any Issuer Free Writing Prospectus or the Time of Sale Information, or arise out of or are based upon the

omission or alleged omission to state therein a material fact necessary in order to make the statements therein, in the light of the

circumstances under which they were made, not misleading, in each case to the extent, but only to the extent, that such untrue statement

or alleged untrue statement or omission or alleged omission was made in any Issuer Free Writing Prospectus, the Time of Sale Information,

the Registration Statement, any Preliminary Prospectus, the Prospectus as amended or supplemented and any other prospectus relating to

the First Mortgage Bonds, or any such amendment or supplement of or to the foregoing, in reliance upon and in conformity with written

information furnished to the Company by such Underwriter through the Representatives expressly for use in any Issuer Free Writing Prospectus,

the Time of Sale Information, the Registration Statement, any Preliminary Prospectus, the Prospectus as amended or supplemented and any

other prospectus relating to the First Mortgage Bonds, or any such amendment or supplement of or to the foregoing, it being understood

and agreed that the only such information consists of the following: (i) the third paragraph of text under the caption “Underwriting”

in the Specified Preliminary Prospectus and the Prospectus, concerning the terms of the offering by the Underwriters, (ii) the third

and fourth sentences of the fifth paragraph of text under the caption “Underwriting” in the Specified Preliminary Prospectus

and the Prospectus, concerning market-making by the Underwriters, and (iii) the sixth and seventh paragraphs of text under the caption

“Underwriting” in the Specified Preliminary Prospectus and the Prospectus, concerning overallotment, stabilization, short-positions

and penalty bids; and will reimburse the Company for any legal or other expenses reasonably incurred by the Company in connection with

investigating or defending any such action or claim as such expenses are incurred.

after receipt by an indemnified party under Section 9(a) or Section 9(b) hereof of notice of the commencement of

any action, such indemnified party shall, if a claim in respect thereof is to be made against the indemnifying party under Section 9(a) or

Section 9(b) hereof, notify the indemnifying party in writing of the commencement thereof; but the omission so to notify the

indemnifying party shall not relieve it from any liability except to the extent that it has been materially prejudiced by such failure

or from any liability which it may have to any indemnified party other than under Section 9(a) or Section 9(b) hereof.

In case any such action shall be brought against any indemnified party and it shall notify the indemnifying party of the commencement

thereof, the indemnifying party shall be entitled to participate therein and, to the extent that it shall wish, jointly with any other

indemnifying party similarly notified, to assume the defense thereof, with counsel satisfactory to such indemnified party (who shall

not, except with the consent of the indemnified party, be counsel to the indemnifying party), and, after notice from the indemnifying

party to such indemnified party of its election so to assume the defense thereof, the indemnifying party shall not be liable to such

indemnified party under Section 9(a) or Section 9(b) hereof for any legal expenses of other counsel or any other

expenses, in each case subsequently incurred by such indemnified party, in connection with the defense thereof other than reasonable

costs of investigation. Notwithstanding the indemnifying party’s election to appoint counsel to represent the indemnified party

in any such action, the indemnified party shall have the right to employ separate counsel (including local counsel), and the indemnifying

party shall bear the reasonable fees, costs and expenses of such separate counsel if (i) the use of counsel chosen by the indemnifying

party to represent the indemnified party would present such counsel with a conflict of interest; (ii) the actual or potential defendants

in, or targets of, any such action include both the indemnified party and the indemnifying party and the indemnified party shall have

reasonably concluded that there may be legal defenses available to it or other indemnified parties that are different from or additional

to those available to the indemnifying party; (iii) the indemnifying party shall not have employed counsel satisfactory to the indemnified

party to represent the indemnified party within a reasonable time after notice of the institution of any such action; or (iv) the

indemnifying party shall authorize the indemnified party to employ separate counsel at the expense of the indemnifying party. No indemnifying

party shall, without the written consent of the indemnified party, effect the settlement or compromise of, or consent to the entry of

any judgment with respect to, any pending or threatened action or claim in respect of which indemnification or contribution may be sought

hereunder (whether or not the indemnified party is an actual or potential party to such action or claim) unless such settlement, compromise

or judgment (i) includes an unconditional release of the indemnified party from all liability arising out of such action or claim

and (ii) does not include a statement as to or an admission of fault, culpability or a failure to act, by or on behalf of any indemnified

party.

(d)            If

the indemnification provided for in this Section 9 is unavailable to or insufficient to hold harmless an indemnified party under

Section 9(a) or Section 9(b) hereof in respect of any losses, claims, damages or liabilities (or actions in respect

thereof) referred to therein, then each indemnifying party shall contribute to the amount paid or payable by such indemnified party as

a result of such losses, claims, damages or liabilities (or actions in respect thereof) in such proportion as is appropriate to reflect

the relative benefits received by the Company on the one hand and the Underwriters of the First Mortgage Bonds on the other hand from

the offering of the First Mortgage Bonds to which such loss, claim, damage or liability (or action in respect thereof) relates. If, however,

the allocation provided by the immediately preceding sentence is not permitted by applicable law or if the indemnified party failed to

give the notice required under Section 9(c) hereof, then each indemnifying party shall contribute to such amount paid or payable

by such indemnified party in such proportion as is appropriate to reflect not only such relative benefits but also the relative fault

of the Company on the one hand and the Underwriters of the First Mortgage Bonds on the other hand in connection with the statements or

omissions which resulted in such losses, claims, damages or liabilities (or actions in respect thereof), as well as any other relevant

equitable considerations. The relative benefits received by the Company on the one hand and such Underwriters on the other hand shall

be deemed to be in the same proportion as the total net proceeds from such offering (before deducting expenses) received by the Company

bear to the total underwriting discounts and commissions received by such Underwriters. The relative fault of the Company on the one

hand and such Underwriters on the other hand shall be determined by reference to, among other things, whether the untrue or alleged untrue

statement of a material fact or the omission or alleged omission to state a material fact relates to information supplied by the Company

on the one hand or such Underwriters on the other hand and the parties’ relative intent, knowledge, access to information and opportunity

to correct or prevent such statement or omission. The Company and the Underwriters agree that it would not be just and equitable if contribution

pursuant to this Section 9(d) were determined by pro rata allocation (even if the Underwriters were treated as one entity for

such purpose) or by any other method of allocation which does not take account of the equitable considerations referred to above in this

Section 9(d). The amount paid or payable by an indemnified party as a result of the losses, claims, damages or liabilities (or actions

in respect thereof) referred to above in this Section 9(d) shall be deemed to include any legal or other expenses reasonably

incurred by such indemnified party in connection with investigating or defending any such action or claim. Notwithstanding the provisions

of this Section 9(d), no Underwriter shall be required to contribute any amount in excess of the amount by which the total price

at which the First Mortgage Bonds underwritten by it and distributed to the public were offered to the public exceeds the amount of any

damages which such Underwriter has otherwise been required to pay by reason of such untrue or alleged untrue statement or omission or

alleged omission. No person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Act) shall be

entitled to contribution from any person who was not guilty of such fraudulent misrepresentation. The obligations of the Underwriters

of the First Mortgage Bonds in this Section 9(d) to contribute are several in proportion to their respective underwriting obligations

with respect to such First Mortgage Bonds and not joint.

(e)            The

obligations of the Company under this Section 9 shall be in addition to any liability which the Company may otherwise have and shall

extend, upon the same terms and conditions, to each person, if any, who controls any Underwriter within the meaning of the Act; and the

obligations of the Underwriters under this Section 9 shall be in addition to any liability which the respective Underwriters may

otherwise have and shall extend, upon the same terms and conditions, to each officer and director of the Company and to each person,

if any, who controls the Company within the meaning of the Act.

10.            Defaulting

Underwriters.

(a)            If

any Underwriter shall default in its obligation to purchase the First Mortgage Bonds which it has agreed to purchase under the Pricing

Agreement relating to such First Mortgage Bonds, the Representatives may in their discretion arrange for themselves or another party

or other parties to purchase such First Mortgage Bonds on the terms contained herein. If within 36 hours after such default by any Underwriter

the Representatives do not arrange for the purchase of such First Mortgage Bonds, then the Company shall be entitled to a further period

of 36 hours within which to procure another party or other parties satisfactory to the Representatives to purchase such First Mortgage

Bonds on such terms. In the event that, within the respective prescribed periods, the Representatives notify the Company that they have

so arranged for the purchase of such First Mortgage Bonds, or the Company notifies the Representatives that it has so arranged for the

purchase of such First Mortgage Bonds, the Representatives or the Company shall have the right to postpone the Time of Delivery for such

First Mortgage Bonds for a period of not more than seven days, in order to effect whatever changes may thereby be made necessary in the

Registration Statement, the Time of Sale Information or the Prospectus as amended or supplemented, or in any other documents or arrangements,

and the Company agrees to file promptly any amendments or supplements to the Registration Statement, the Time of Sale Information or

the Prospectus which in the opinion of the Representatives may thereby be made necessary. The term “Underwriter” as used

in this Underwriting Agreement shall include any person substituted under this Section 10 with like effect as if such person had

originally been a party to the Pricing Agreement with respect to such First Mortgage Bonds.

(b)            If,

after giving effect to any arrangements for the purchase of the First Mortgage Bonds of a defaulting Underwriter or Underwriters by the

Representatives and the Company as provided in Section 10(a) hereof, the aggregate principal amount of such First Mortgage

Bonds which remains unpurchased does not exceed one-eleventh of the aggregate principal amount of the First Mortgage Bonds, then the

Company shall have the right to require each non-defaulting Underwriter to purchase the principal amount of the First Mortgage Bonds

which such Underwriter agreed to purchase under the Pricing Agreement relating to such First Mortgage Bonds and, in addition, to require

each non-defaulting Underwriter to purchase its pro rata share (based on the principal amount of the First Mortgage Bonds which such

Underwriter agreed to purchase under such Pricing Agreement) of the First Mortgage Bonds of such defaulting Underwriter or Underwriters

for which such arrangements have not been made; but nothing herein shall relieve a defaulting Underwriter from liability for its default.

after giving effect to any arrangements for the purchase of the First Mortgage Bonds of a defaulting Underwriter or Underwriters by the

Representatives and the Company as provided in Section 10(a) hereof, the aggregate principal amount of the First Mortgage Bonds

which remains unpurchased exceeds one-eleventh of the aggregate principal amount of the First Mortgage Bonds, as referred to in Section 10(b) hereof,

or if the Company shall not exercise the right described in Section 10(b) hereof to require non-defaulting Underwriters to

purchase the First Mortgage Bonds of a defaulting Underwriter or Underwriters, then the Pricing Agreement relating to such First Mortgage

Bonds shall thereupon terminate, without liability on the part of any non-defaulting Underwriter or the Company, except for the expenses

to be borne by the Company and the Underwriters as provided in Section 6 hereof and the indemnity and contribution agreements in

Section 9 hereof; but nothing herein shall relieve a defaulting Underwriter from liability for its default.

11.            Survival.

The respective indemnities, agreements, representations, warranties and other statements of the Company and the several Underwriters,

as set forth in this Underwriting Agreement or made by or on behalf of them, respectively, pursuant to this Underwriting Agreement, shall

remain in full force and effect, regardless of any investigation (or any statement as to the results thereof) made by or on behalf of

any Underwriter or any controlling person of any Underwriter, or the Company, or any officer or director or controlling person of the

Company, and shall survive delivery of and payment for the First Mortgage Bonds.

12.            Termination.

If any Pricing Agreement shall be terminated pursuant to Section 10 hereof, the Company shall not then be under any liability to

any Underwriter with respect to the First Mortgage Bonds covered by such Pricing Agreement except as provided in Sections 6 and 9 hereof;

but, if for any other reason the First Mortgage Bonds are not delivered by or on behalf of the Company as provided herein or the Company

does not comply with its other obligations as provided herein, the Company will reimburse the Underwriters through the Representatives

for all out-of-pocket expenses approved in writing by the Representatives, including fees and disbursements of counsel for the Underwriters,

reasonably incurred by the Underwriters in making preparations for the purchase, sale and delivery of such First Mortgage Bonds, but

the Company shall then be under no further liability to any Underwriter with respect to such First Mortgage Bonds, except as provided

in Sections 6 and 9 hereof.

13.            Notices.

In all dealings hereunder, the Representatives of the Underwriters of the First Mortgage Bonds shall act on behalf of each of such Underwriters,

and the parties hereto shall be entitled to act and rely upon any statement, request, notice or agreement on behalf of any Underwriter

made or given by such Representatives jointly.

All statements, requests,

notices and agreements hereunder shall be in writing and shall be deemed to have been duly given if mailed, and if to the Underwriters

shall be delivered or sent by mail to the address of the Representatives as set forth in the Pricing Agreement; and if to the Company

shall be delivered or sent by mail to the address of the Company set forth in the Registration Statement: Attention: Secretary.

14.            No

Third Party Beneficiaries. This Underwriting Agreement and each Pricing Agreement shall be binding upon, and inure solely to the

benefit of, the Underwriters, the Company and, to the extent provided in Sections 9 and 11 hereof, the officers and directors of the

Company and each person who controls the Company or any Underwriter, and their respective heirs, executors, administrators, successors

and assigns, and no other person shall acquire or have any right under or by virtue of this Underwriting Agreement or any such Pricing

Agreement. No purchaser of any of the First Mortgage Bonds from any Underwriter shall be deemed a successor or assign by reason merely

of such purchase.

15.            Miscellaneous.

Time shall be of the essence of each Pricing Agreement. As used herein, “business day” shall mean any day when the Commission’s

office in Washington, D.C. is open for business.

16.            Governing

Law. This Underwriting Agreement and each Pricing Agreement shall be governed by and construed in accordance with the laws of the

State of New York.

17.            Waiver

of Jury Trial. The Company and each of the Underwriters hereby waive their respective rights to jury trial with respect to any litigation

arising under, or in connection with, this Underwriting Agreement and each Pricing Agreement.

18.            Counterparts.

This Underwriting Agreement and each Pricing Agreement may be executed by any one or more of the parties hereto and thereto in any number

of counterparts, each of which shall be deemed to be an original, but all such respective counterparts shall together constitute one

and the same instrument. The words “execution,” “signed,” “signature,” “delivery” and

words of like import in or relating to this Underwriting Agreement and each Pricing Agreement or any document to be signed in connection

with this Underwriting Agreement and each Pricing Agreement shall be deemed to include electronic signatures complying with the U.S.

federal ESIGN Act of 2000 or the New York Electronic Signature and Records Act or deliveries or the keeping of records in electronic

form, each of which shall be of the same legal effect, validity or enforceability as a manually executed signature, physical delivery

thereof or the use of a paper-based recordkeeping system, as the case may be, and the parties hereto consent to conduct the transactions

contemplated hereunder by electronic means.

19.            No

Fiduciary Duty. The Company hereby acknowledges that the Underwriters are acting solely in the capacity of an arm’s-length

contractual counterparty to the Company with respect to the offering of First Mortgage Bonds contemplated hereby (including in connection

with determining the terms of the offering) and not as a financial advisor or a fiduciary to, or an agent of, the Company or any other

person. Additionally, neither the Representatives nor any other Underwriters are advising the Company or any other person as to any legal,

tax, investment, accounting or regulatory matters in any jurisdiction with respect to the offering of First Mortgage Bonds contemplated

hereby. The Company shall consult with its own advisors concerning such matters and shall be responsible for making its own independent

investigation and appraisal of the transactions contemplated hereby, and the Underwriters shall have no responsibility or liability to

the Company with respect thereto. Any review by the Underwriters of the Company, the transactions contemplated hereby or other matters

relating to such transactions will be performed solely for the benefit of the Underwriters and shall not be on behalf of the Company.

20.            Qualified

Financial Contracts. In the event that any Underwriter that is a Covered Entity (as defined below) becomes subject to a proceeding

under a U.S. Special Resolution Regime (as defined below), the transfer from such Underwriter of this Underwriting Agreement, and any

interest and obligation in or under this Underwriting Agreement, will be effective to the same extent as the transfer would be effective

under the U.S. Special Resolution Regime if this Underwriting Agreement, and any such interest and obligation, were governed by the laws

of the United States or a state of the United States. In the event that any Underwriter that is a Covered Entity or a BHC Act Affiliate

(as defined below) of such Underwriter becomes subject to a proceeding under a U.S. Special Resolution Regime, Default Rights (as defined

below) under this Underwriting Agreement that may be exercised against such Underwriter are permitted to be exercised to no greater extent

than such Default Rights could be exercised under the U.S. Special Resolution Regime if this Underwriting Agreement were governed by

the laws of the United States or a state of the United States. “BHC Act Affiliate” has the meaning assigned to the

term “affiliate” in, and shall be interpreted in accordance with, 12 U.S.C. § 1841(k). “Covered Entity”

means any of the following: (i) a “covered entity” as that term is defined in, and interpreted in accordance with, 12

C.F.R. § 252.82(b); (ii) a “covered bank” as that term is defined in, and interpreted in accordance with, 12 C.F.R.

§ 47.3(b); or (iii) a “covered FSI” as that term is defined in, and interpreted in accordance with, 12 C.F.R. § 382.2(b).

“Default Right” has the meaning assigned to that term in, and shall be interpreted in accordance with, 12 C.F.R. §§

252.81, 47.2 or 382.1, as applicable. “U.S. Special Resolution Regime” means each of (x) the Federal Deposit

Insurance Act and the regulations promulgated thereunder and (y) Title II of the Dodd-Frank Wall Street Reform and Consumer Protection

Act and the regulations promulgated thereunder.

[Signature Page Follows]

If the foregoing is in accordance

with your understanding, please sign and return to us a counterpart hereof.

Very truly yours,

Union Electric Company

By: /s/ Mitchell J. Lansford

Name: Mitchell J. Lansford

Title: Vice President and Treasurer

Accepted as of the date hereof:

Fifth Third Securities, Inc.

Mizuho Securities USA LLC

TD Securities (USA) LLC

Truist Securities, Inc.

U.S. Bancorp Investments, Inc.

As Representatives of the several Underwriters

Fifth Third Securities, Inc.

Mizuho Securities usa llc

By:

/s/ Paul McKeown

By:

/s/ Stephen E. Leamer

Name: Paul McKeown

Name: Stephen E. Leamer

Title: Managing Director

TD Securities

(USA) LLC

Truist securities, inc.

By:

/s/ Luiz Lanfredi

By:

/s/ Rob Nordlinger

Name: Luiz Lanfredi

Name: Rob Nordlinger

Title: Managing Director

Title: Managing Director

U.s. Bancorp investments, inc.

By:

/s/ Michael Priore

Name: Michael Priore

Title: Managing Director

[Signature Page to the

Underwriting Agreement]

ANNEX I

Pricing Agreement

June 15, 2026

Fifth Third Securities, Inc.

Mizuho Securities USA LLC

TD Securities (USA) LLC

Truist Securities, Inc.

U.S. Bancorp Investments, Inc.

As Representatives of the several Underwriters

named in Schedule I hereto

c/o Fifth Third Securities, Inc.

38 Fountain Square Plaza

Cincinnati, Ohio 45263

Mizuho Securities USA LLC

1271 Avenue of the Americas

New York, New York 10020

TD Securities (USA) LLC

1 Vanderbilt Avenue, 11th Floor

New York, New York 10017

Truist Securities, Inc.

50 Hudson Yards, 70th Floor

New York, New York 10001

U.S. Bancorp Investments, Inc.

214 North Tryon Street, 26th Floor

Charlotte, North Carolina 28202

Ladies and Gentlemen:

Union Electric Company, a

Missouri corporation (the “Company”), proposes, subject to the terms and conditions stated herein and in the Underwriting

Agreement, dated June 15, 2026 (the “Underwriting Agreement”), between the Company on the one hand and the Underwriters

named in Schedule I hereto (the “Underwriters”), for whom Fifth Third Securities, Inc., Mizuho Securities USA

LLC, TD Securities (USA) LLC, Truist Securities, Inc. and U.S. Bancorp Investments, Inc. are acting as representatives (the

“Representatives”), on the other hand, to issue and sell to the Underwriters the First Mortgage Bonds specified in

Schedule II hereto (the “First Mortgage Bonds”) with the terms set forth in Schedule III hereto. Each of the

provisions of the Underwriting Agreement is incorporated herein by reference in its entirety, and shall be deemed to be a part of this

Pricing Agreement to the same extent as if such provisions had been set forth in full herein, and each of the representations and warranties

set forth therein shall be deemed to have been made at and as of the date of this Pricing Agreement. Each reference to the Representatives

herein and in the provisions of the Underwriting Agreement so incorporated by reference shall be deemed to refer to you. Unless otherwise

defined herein, terms defined in the Underwriting Agreement are used herein as therein defined. Each of the Representatives designated

to act on behalf of the other Representatives and on behalf of each of the other Underwriters of the First Mortgage Bonds pursuant to

Section 13 of the Underwriting Agreement and the address of the Representatives referred to in such Section 13 are set forth

at the end of Schedule II hereto.

I-1

Subject to the terms and

conditions set forth herein and in the Underwriting Agreement incorporated herein by reference, the Company agrees to issue and sell

to each of the Underwriters, and each of the Underwriters agrees, severally and not jointly, to purchase from the Company, at the time

and place and at the purchase price to the Underwriters set forth in Schedule II hereto, the principal amount of the First Mortgage Bonds

set forth opposite the name of such Underwriter in Schedule I hereto.

For all purposes of the Underwriting

Agreement, (i) the “Time of Sale” means 2:45 p.m. (New York City time) on the date hereof and (ii) the

“Time of Sale Information,” collectively, means the following information: the Specified Preliminary Prospectus, as

amended or supplemented immediately prior to the Time of Sale (including the documents incorporated therein by reference as of the Time

of Sale), as supplemented by the final term sheet prepared and filed pursuant to Section 5(a) of the Underwriting Agreement

and referred to on Part A of Annex II thereof.

The purchase price for the

First Mortgage Bonds shall be 98.449% of the aggregate principal amount thereof.

[Signature Page Follows]

I-2

If the foregoing is in accordance

with your understanding, please sign and return to us a counterpart hereof, and upon acceptance hereof by you, on behalf of each of the

Underwriters, this letter and such acceptance hereof, including the provisions of the Underwriting Agreement incorporated herein by reference,

shall constitute a binding agreement between each of the Underwriters and the Company. It is understood that your acceptance of this

letter on behalf of each of the Underwriters is or will be pursuant to the authority set forth in an Agreement among Underwriters, the

form of which shall be submitted to the Company for examination upon request, but without warranty on the part of the Representatives

as to the authority of the other signers thereof.

Very truly yours,

Union Electric Company

By:

Name: Mitchell J. Lansford

Title: Vice President and Treasurer

Accepted as of the date hereof:

Fifth Third Securities, Inc.

Mizuho Securities USA LLC

TD Securities (USA) LLC

Truist Securities, Inc.

U.S. Bancorp Investments, Inc.

As Representatives

of the several Underwriters

Fifth Third Securities, Inc.

Mizuho Securities USA LLC

By:

Name:

Title:

TD Securities

(USA) LLC

Truist Securities, Inc.

By:

Name:

Title:

[Signature Page to the

Pricing Agreement]

U.s. Bancorp investments, inc.

By:

Name:

Title:

[Signature Page to

the Pricing Agreement]

SCHEDULE I

Underwriter

Principal

Amount of

First Mortgage Bonds

to be Purchased

Fifth Third Securities, Inc.

$ 90,000,000

Mizuho Securities USA LLC

90,000,000

TD Securities (USA) LLC

90,000,000

Truist Securities, Inc.

90,000,000

U.S. Bancorp Investments, Inc.

90,000,000

BNY Mellon Capital Markets, LLC

50,000,000

Total

$ 500,000,000

I-I-1

SCHEDULE II

Title of First Mortgage Bonds:

$500,000,000 5.75% First Mortgage Bonds due 2056

Aggregate principal amount:

$500,000,000

“First Mortgage Bonds”

for purposes of the Underwriting Agreement refers to the $500,000,000 principal amount of the 5.75% First Mortgage Bonds due 2056 to

be issued at the Time of Delivery.

Offering Price:

99.324% of the principal amount of the First Mortgage Bonds,

plus accrued interest, if any, from the Time of Delivery

Purchase Price paid by the Underwriters:

98.449% of the principal amount of the First Mortgage Bonds

Form of First Mortgage Bonds:

Book-entry only form represented by

one or more global securities deposited with The Depository Trust Company (“DTC”) or its designated custodian, to

be made available for checking (if delivery shall be made otherwise than through the facilities of DTC) by the Representatives at least

twenty-four hours prior to the Time of Delivery at such place as may be agreed upon by the Company and the Representatives.

Time of Delivery:

10:00 a.m. (New York City time),

June 29, 2026

Supplemental Indenture relating to First Mortgage Bonds:

Dated June 1, 2026

Maturity:

September 15, 2056

Interest Rate:

5.75%

Interest Payment Dates:

March 15 and September 15,

commencing March 15, 2027

Redemption Provisions:

The First Mortgage Bonds may be redeemed

at the option of the Company as set forth in the Prospectus, as supplemented, relating to such First Mortgage Bonds.

Sinking Fund Provisions:

No sinking fund provisions

I-II-1

Defeasance provisions:

As set forth in the Mortgage

Closing location for delivery of First Mortgage Bonds:

Morgan, Lewis &

Bockius LLP, 101 Park Avenue, New York, New York 10178

Designated Representatives:

Fifth Third Securities, Inc.

Mizuho Securities USA LLC

TD Securities (USA) LLC

Truist Securities, Inc.

U.S. Bancorp Investments, Inc.

Addresses for Notices, etc.:

Fifth Third Securities, Inc.

38 Fountain Square Plaza

Cincinnati, Ohio 45263

Attention: Debt Capital Markets/Legal

Mizuho Securities USA LLC

1271 Avenue of the Americas

New York, New York 10020

Attention: Debt Capital Markets

TD Securities (USA) LLC

1 Vanderbilt Avenue, 11th Floor

New York, New York 10017

Attention: DCM – Transaction Advisory

Truist Securities, Inc.

50 Hudson Yards, 70th Floor

New York, New York 10001

Attention: Investment Grade Debt Capital Markets

U.S. Bancorp Investments, Inc.

214 N. Tryon Street, 26th Floor

Charlotte, North Carolina 28202

Attention: High Grade Syndicate

I-II-2

SCHEDULE III

Union Electric Company

Pricing Term Sheet

June 15, 2026

Issue:

5.75%

First Mortgage Bonds due 2056

Principal

Amount:

$500,000,000

Coupon

(Interest Rate):

5.75% per

annum

Maturity

Date:

September 15,

2056

Benchmark

Treasury:

4.75% due

February 15, 2056

Benchmark

Treasury Price:

96-16+

Benchmark

Treasury Yield:

4.976%

Spread

to Benchmark Treasury:

+82 basis

points

Re-offer

Yield:

5.796%

Offering

Price (Issue Price):

99.324% of

the principal amount

Interest

Payment Dates:

March 15

and September 15, commencing March 15, 2027

Optional

Redemption:

Prior to

March 15, 2056 (the “Par Call Date”) redeemable, in whole or in part, at any time at a redemption price equal to

the greater of (1)(a) the sum of the present values of the remaining scheduled payments of principal and interest thereon discounted

to the redemption date (assuming the First Mortgage Bonds to be redeemed matured on the Par Call Date) on a semi-annual basis at

the Treasury Rate plus 12.5 basis points less (b) interest accrued to the redemption date, and (2) 100% of the principal

amount of the First Mortgage Bonds to be redeemed, plus, in either case, accrued and unpaid interest thereon to the redemption date.

On or after the Par Call Date, redeemable, in whole or in part, at any time at a redemption price equal to 100% of the principal

amount of the First Mortgage Bonds being redeemed plus accrued and unpaid interest thereon to the redemption date.

I-III-1

Right

to Redeem for Tax Credit Event:

Redeemable

upon the occurrence of a Tax Credit Event, in whole but not in part, at 101% of the principal amount of the First Mortgage Bonds

to be redeemed, plus accrued and unpaid interest thereon to the redemption date (provided, that the related notice of redemption

must be sent by the later of (a) December 31, 2026 and (b) six months from the date of issuance of the First Mortgage

Bonds).

Expected

Ratings (Moody’s/S&P)*:

{Intentionally

omitted}

Trade

Date:

June 15,

2026

Settlement

Date:

June 29,

2026 (T+9)**

CUSIP

/ ISIN:

906548 DD1

/ US906548DD17

Joint

Book-Running Managers:

Fifth Third

Securities, Inc.

Mizuho Securities

USA LLC

TD Securities

(USA) LLC

Truist Securities, Inc.

U.S. Bancorp

Investments, Inc.

BNY Mellon

Capital Markets, LLC

The terms “Treasury Rate” and “Tax Credit Event”

have the respective meanings ascribed to those terms in the Issuer’s Preliminary Prospectus Supplement, dated June 15, 2026.

* A security rating is not a recommendation to buy, sell or hold securities

and should be evaluated independently of any other rating. The rating is subject to revision or withdrawal at any time by the assigning

rating organization.

** It is expected that delivery of the First Mortgage Bonds will be

made against payment therefor on or about the Settlement Date specified above. Under Rule 15c6-1 under the Securities Exchange Act

of 1934, as amended, trades in the secondary market generally are required to settle in one business day, unless the parties to a trade

expressly agree otherwise. Accordingly, purchasers who wish to trade the First Mortgage Bonds more than one business day prior to the

scheduled settlement date will be required, by virtue of the fact that the First Mortgage Bonds initially are expected to settle in T+9,

to specify an alternative settlement arrangement at the time of any such trade to prevent a failed settlement.

The Issuer has filed a registration statement (including a prospectus)

with the SEC for the offering to which this communication relates. Before you invest, you should read the prospectus in that registration

statement and other documents the Issuer has filed with the SEC for more complete information about the Issuer and this offering. You

may get these documents for free by visiting EDGAR on the SEC’s website at www.sec.gov. Alternatively, the Issuer, any underwriter

or any dealer participating in the offering will arrange to send you the prospectus if you request it by contacting (i) Fifth Third

Securities, Inc. toll-free at 1-866-531-5353, (ii) Mizuho Securities USA LLC toll-free at 1-866-271-7403, (iii) TD Securities

(USA) LLC toll-free at 1-855-495-9846, (iv) Truist Securities, Inc. toll-free at 1-800-685-4786 or (v) U.S. Bancorp Investments, Inc.

toll-free at 1-877-558-2607.

I-III-2

ANNEX II

A)            Issuer

Free Writing Prospectuses To Be Included As Time of Sale Information:

Pricing Term Sheet dated June 15, 2026

B)            Issuer

Free Writing Prospectuses Not Included As Time of Sale Information:

None

II-1

EX-4.2 — EXHIBIT 4.2

EX-4.2

Filename: tm2619063d1_ex4-2.htm · Sequence: 3

Exhibit 4.2

SUPPLEMENTAL INDENTURE

DATED JUNE 1, 2026

UNION ELECTRIC COMPANY

THE BANK OF NEW YORK MELLON,

AS TRUSTEE

(SUPPLEMENTAL TO THE INDENTURE OF MORTGAGE

AND DEED OF TRUST DATED

JUNE 15, 1937, AS AMENDED, EXECUTED BY UNION ELECTRIC COMPANY TO

THE BANK OF NEW YORK MELLON, AS TRUSTEE)

5.75%

First Mortgage Bonds due 2056

This instrument was prepared by David M. Feinberg, Esq.,

Executive Vice President, General Counsel and Secretary of Union Electric Company, 1901 Chouteau Avenue, St. Louis, Missouri 63103,

(314) 621-3222.

WHEN RECORDED MAIL TO:

Jonathan T. Shade

Union Electric Company

1901 Chouteau Avenue

St. Louis, MO 63103

SUPPLEMENTAL

INDENTURE, dated the 1st day of June, Two thousand and twenty-six (2026) made by and between UNION ELECTRIC COMPANY,

a corporation organized and existing under the laws of the State of Missouri (hereinafter called the “Company”), party of

the first part, and The Bank of New York Mellon, formerly The Bank of New York (successor

trustee to Bank of America, National Association, formerly Boatmen’s Trust Company), a bank existing under the laws of the State

of New York (hereinafter called the “Trustee”), as Trustee under the Indenture of Mortgage and Deed of Trust dated June 15,

1937, hereinafter mentioned, party of the second part:

WHEREAS,

the Company has heretofore executed and delivered to the Trustee its Indenture of Mortgage and Deed of Trust, dated June 15, 1937,

as amended May 1, 1941, April 1, 1971, February 1, 1974, July 7, 1980, February 1, 2000, August 15, 2002

and May 15, 2012 (said Indenture of Mortgage and Deed of Trust as so amended, being hereinafter referred to as the “Original

Indenture”), to secure the payment of the principal of and the interest (and premium, if any) on all bonds at any time issued and

outstanding thereunder, and indentures supplemental thereto dated June 15, 1937, May 1, 1941, March 17, 1942, April 13,

1945, April 27, 1945, October 1, 1945, April 11, 1947, April 13, 1949, September 13, 1950, December 1,

1950, September 20, 1951, May 1, 1952, March 1, 1954, May 1, 1955, August 31, 1955, April 1, 1956, July 1,

1956, August 1, 1957, February 1, 1958, March 1, 1958, November 5, 1958, March 16, 1959, June 24, 1959,

December 11, 1959, August 17, 1960, September 1, 1960, October 24, 1960, June 30, 1961, July 1, 1961, August 9,

1962, September 30, 1963, November 1, 1963, March 12, 1965, April 1, 1965, April 14, 1966, May 1, 1966,

February 17, 1967, March 1, 1967, February 19, 1968, March 15, 1968, August 21, 1968, April 7, 1969, May 1,

1969, September 12, 1969, October 1, 1969, March 26, 1970, April 1, 1970, June 12, 1970, January 1, 1971,

April 1, 1971, September 15, 1971, December 3, 1973, February 1, 1974, April 25, 1974, February 3, 1975,

March 1, 1975, June 11, 1975, May 12, 1976, August 16, 1976, April 26, 1977, October 15, 1977, November 7,

1977, December 1, 1977, August 1, 1978, October 12, 1979, November 1, 1979, July 7, 1980, August 1, 1980,

August 20, 1980, February 1, 1981, October 8, 1981, August 27, 1982, September 1, 1982, December 15, 1982,

March 1, 1983, June 21, 1984, December 12, 1984, June 11, 1985, March 1, 1986, May 1, 1986, May 1,

1990, December 1, 1991, December 4, 1991, January 1, 1992, September 30, 1992, October 1, 1992, December 1,

1992, February 1, 1993, February 18, 1993, May 1, 1993, August 1, 1993, October 1, 1993, January 1, 1994,

February 1, 2000, August 15, 2002, March 5, 2003, April 1, 2003, July 15, 2003, October 1, 2003, February 1,

2004 (eight separate indentures supplemental thereto), May 1, 2004, September 1, 2004, January 1, 2005, July 1, 2005,

December 1, 2005, June 1, 2007, April 1, 2008, June 1, 2008, March 1, 2009, September 1, 2012, April 1,

2014, March 15, 2015, June 1, 2017, April 1, 2018, March 1, 2019, September 15, 2019, March 1, 2020, October 1,

2020, June 1, 2021, March 1, 2022, February 1, 2023, January 1, 2024, March 1, 2024, September 1, 2024, March

1, 2025 and February 1, 2026, respectively, have heretofore been entered into between the Company and the Trustee; and

WHEREAS,

the following Bonds have heretofore been issued by the Company under the Original Indenture and remain outstanding:

(1)

$184,000,000 principal amount of First Mortgage Bonds, Senior Notes Series BB, which are described in the Supplemental Indenture

dated March 5, 2003, all of which are outstanding at the date of the execution hereof;

(2)

$60,000,000 principal amount of First Mortgage Bonds, Environmental Improvement Series 2004A (1998A Bonds), which are described

in the Supplemental Indenture dated February 1, 2004, all of which are outstanding at the date of the execution hereof;

(3)

$50,000,000 principal amount of First Mortgage Bonds, Environmental Improvement Series 2004B (1998B Bonds), which are described

in the Supplemental Indenture dated February 1, 2004, all of which are outstanding at the date of the execution hereof;

(4)

$50,000,000 principal amount of First Mortgage Bonds, Environmental Improvement Series 2004C (1998C Bonds), which are described

in the Supplemental Indenture dated February 1, 2004, all of which are outstanding at the date of the execution hereof;

(5)

$300,000,000 principal amount of First Mortgage Bonds, Senior Notes Series II, which are described in the Supplemental Indenture

dated July 1, 2005, all of which are outstanding at the date of the execution hereof;

(6)

$350,000,000 principal amount of First Mortgage Bonds, Senior Notes, Series NN, which are described in the Supplemental Indenture

dated March 1, 2009, all of which are outstanding at the date of the execution hereof;

(7)

$485,000,000 principal amount of First Mortgage Bonds, Senior Notes, Series OO, which are described in the Supplemental Indenture

dated September 1, 2012, all of which are outstanding at the date of the execution hereof;

(8)

$400,000,000 principal amount of First Mortgage Bonds, Senior Notes, Series QQ, which are described in the Supplemental Indenture

dated March 15, 2015, all of which are outstanding at the date of the execution hereof;

(9)

$400,000,000 principal amount of First Mortgage Bonds, Senior Notes, Series RR, which are described in the Supplemental Indenture

dated June 1, 2017, all of which are outstanding at the date of the execution hereof;

(10)

$425,000,000 principal amount of 4.000% First Mortgage Bonds, due 2048, which are described in the Supplemental Indenture dated

April 1, 2018, all of which are outstanding at the date of the execution hereof;

(11)

$450,000,000 principal amount of 3.50% First Mortgage Bonds, due 2029, which are described in the Supplemental Indenture dated

March 1, 2019, all of which are outstanding at the date of the execution hereof;

(12)

$330,000,000 principal amount of 3.25% First Mortgage Bonds due 2049, which are described in the Supplemental Indenture dated

September 15, 2019, all of which are outstanding at the date of the execution hereof;

(13)

$465,000,000 principal amount of 2.95% First Mortgage Bonds due 2030, which are described in the Supplemental Indenture dated

March 1, 2020, all of which are outstanding at the date of the execution hereof;

(14)

$550,000,000 principal amount of 2.625% First Mortgage Bonds due 2051, which are described in the Supplemental Indenture dated

October 1, 2020, all of which are outstanding at the date of the execution hereof;

(15)

$525,000,000 principal amount of 2.15% First Mortgage Bonds due 2032, which are described in the Supplemental Indenture dated

June 1, 2021, all of which are outstanding at the date of the execution hereof;

(16)

$525,000,000 principal amount of 3.90% First Mortgage Bonds due 2052, which are described in the Supplemental Indenture dated

March 1, 2022, all of which are outstanding at the date of the execution hereof;

(17)

$500,000,000 principal amount of 5.45% First Mortgage Bonds due 2053, which are described in the Supplemental Indenture dated

February 1, 2023, all of which are outstanding at the date of the execution hereof;

(18)

$350,000,000 principal amount of 5.25% First Mortgage Bonds due 2054, which are described in the Supplemental Indenture dated

January 1, 2024, all of which are outstanding at the date of the execution hereof;

(19)

$500,000,000 principal amount of 5.20% First Mortgage Bonds due 2034, which are described in the Supplemental Indenture dated

March 1, 2024, all of which are outstanding at the date of the execution hereof;

(20)

$450,000,000 principal amount of 5.125% First Mortgage Bonds due 2055, which are described in the Supplemental Indenture dated

September 1, 2024, all of which are outstanding at the date of the execution hereof;

(21)

$500,000,000 principal amount of 5.25% First Mortgage Bonds due 2035, which are described in the Supplemental Indenture dated

March 1, 2025, all of which are outstanding at the date of the execution hereof;

(22)

$450,000,000 principal amount of 4.80% First Mortgage Bonds due 2036, which are described in the Supplemental Indenture dated

February 1, 2026, all of which are outstanding at the date of the execution hereof; and

(23)

$450,000,000 principal amount of 5.55% First Mortgage Bonds due 2056, which are described in the Supplemental Indenture dated

February 1, 2026, all of which are outstanding at the date of the execution hereof; and

WHEREAS,

the Company on August 31, 1955 acquired all of the properties of Union Electric Power Company, the Subsidiary as defined in Article I

of the Original Indenture, upon the dissolution of the Subsidiary; the Company, by Supplemental Indenture dated August 31, 1955,

conveyed all of the properties so acquired (other than property of the character defined as excepted property in the granting clauses

of the Original Indenture) to the Trustee upon the terms and trusts in the Original Indenture and the indentures supplemental thereto

set forth for the equal and proportionate benefit and security of all present and future holders of the Bonds and coupons issued and

to be issued thereunder, all the shares of stock of the Subsidiary were released from the lien of the Original Indenture; and the Company

became entitled to change the general designation of the Bonds so as to omit the words “and Collateral Trust”; and

WHEREAS,

the Articles of Incorporation of the Company were duly amended on April 23, 1956, to change its corporate name from “Union

Electric Company of Missouri” to “Union Electric Company”; and

WHEREAS,

the Articles of Agreement of the Trustee were duly amended effective on January 4, 1982 to change its corporate name from “St.

Louis Union Trust Company” to “Centerre Trust Company of St. Louis”, and further amended on December 9, 1988,

to change its corporate name from “Centerre Trust Company of St. Louis” to “Boatmen’s Trust Company”;

and

WHEREAS,

that on March 13, 1998, Boatmen’s Trust Company merged into NationsBank, National Association and effective July 5, 1999,

changed its name to Bank of America, National Association; and

WHEREAS,

that on February 1, 2000, The Bank of New York, as transferee of the corporate trust business of Bank of America, National Association

(formerly known as Boatmen’s Trust Company), Trustee under the Original Indenture, became successor Trustee under the Original

Indenture; and

WHEREAS,

that effective as of July 1, 2008, The Bank of New York changed its name to The Bank of New York Mellon; and

WHEREAS,

the Company is entitled at this time to have authenticated and delivered additional Bonds on the basis of “property additions”

upon compliance with and pursuant to the provisions of Section 4 of Article III of the Original Indenture or on the basis of

“refundable Bonds” upon compliance with and pursuant to the provisions of Section 6 of Article III of the Original Indenture;

and

WHEREAS,

the Company desires by this Supplemental Indenture to provide for the creation of a new series of Bonds under the Original Indenture,

to have the designation provided in Article I, Section 1 hereof (herein called the “New Bonds”), and the Original

Indenture provides that certain terms and provisions, as determined by the Board of Directors of the Company, of the Bonds of any particular

series may be expressed in and provided by the execution of an appropriate supplemental indenture; and

WHEREAS,

the Original Indenture provides that the Company and the Trustee may enter into indentures supplemental to the Original Indenture specifically

to convey, transfer and assign to the Trustee and to subject to the lien of the Original Indenture additional properties acquired by

the Company; and

WHEREAS,

the Company, in the exercise of the powers and authority conferred upon and reserved to it under the provisions of the Original Indenture,

and pursuant to appropriate resolutions of the Board of Directors, has duly resolved and determined to make, execute and deliver to the

Trustee this Supplemental Indenture in the form hereof for the purposes herein provided; and

WHEREAS,

all conditions and requirements necessary to make this Supplemental Indenture a valid, binding and legal instrument have been done, performed

and fulfilled and the execution and delivery hereof have been in all respects duly authorized;

NOW, THEREFORE, THIS SUPPLEMENTAL INDENTURE

WITNESSETH:

That, in consideration of the premises and of

the mutual covenants herein contained and of the acceptance of this trust by the Trustee and of the sum of One Dollar duly paid by the

Trustee to the Company at or before the time of the execution of this Supplemental Indenture, and of other valuable considerations, the

receipt whereof is hereby acknowledged, and in order further to secure the payment of the principal of and interest (and premium, if

any) on all Bonds at any time issued and outstanding under the Original Indenture, according to their tenor and effect, the Company has

executed and delivered this Supplemental Indenture and has granted, bargained, sold, warranted, aliened, remised, released, conveyed,

assigned, transferred, mortgaged, pledged, set over and confirmed and by these presents does grant, bargain, sell, warrant, alien, remise,

release, convey, assign, transfer, mortgage, pledge, set over and confirm unto The Bank of New York Mellon, as Trustee, and to its successors

in trust under the Original Indenture forever, all and singular the following described properties (in addition to all other properties

heretofore subjected to the lien of the Original Indenture and not heretofore released from the lien thereof) - that is to say:

FIRST.

ALL (except as in the Original Indenture

expressly excepted) power houses, plants, buildings and other structures, dams, dam sites, substations, heating plants, gas works, holders

and tanks, together with all and singular the electric, heating, gas and mechanical appliances appurtenant thereto of every nature whatsoever,

now owned by the Company, including all and singular the machinery, engines, boilers, furnaces, generators, dynamos, turbines and motors,

and all and every character of mechanical appliance for generating or producing electricity, steam, gas and other agencies for light,

heat, cold, or power or other purposes, and all transmission and distribution systems used for the transmission and distribution of electricity,

steam, gas and other agencies for light, heat, cold or power or any other purpose whatsoever, whether underground or overhead, surface

or otherwise, now owned by the Company, including all poles, towers, posts, wires, cables, conduits, manholes, mains, pipes, tubes, drains,

furnaces, switchboards, transformers, conductors, insulators, supports, meters, lamps, fuses, junction boxes, regulator stations, and

other electric, steam and gas fixtures and apparatus; all of the aforementioned property being located in the City of St. Louis, the

counties of Adair, Atchison, Audrain, Benton, Bollinger, Boone, Butler, Caldwell, Callaway, Camden, Cape Girardeau, Clark, Clay, Clinton,

Cole, Cooper, Crawford, Daviess, Dunklin, Franklin, Gasconade, Howard, Iron, Jefferson, Knox, Lewis, Lincoln, Livingston, Macon, Madison,

Maries, Marion, Miller, Mississippi, Moniteau, Montgomery, Morgan, New Madrid, Osage, Pemiscot, Perry, Pettis, Phelps, Pike, Pulaski,

Ralls, Randolph, Ray, Reynolds, Ripley, St. Charles, St. Francois, Ste. Genevieve, St. Louis, Saline, Schuyler, Scott, Stoddard, Warren,

Washington, and Wayne, Missouri, the counties of Cass, Clay, Hancock, Henderson, Madison, Marion, Perry, Piatt, St. Clair and White,

Illinois, and the counties of Des Moines, Henry, Johnson, Lee, and Washington, Iowa, upon real estate owned by the Company, or occupied

by it under rights to so occupy, which real estate is described in, or added through the provisions of, the Indenture of Mortgage and

Deed of Trust dated June 15, 1937, the Supplemental Indentures dated May 1, 1941, March 17, 1942, April 13, 1945,

April 27, 1945, October 1, 1945, April 11, 1947, April 13, 1949, September 13, 1950, December 1, 1950,

September 20, 1951, May 1, 1952, March 1, 1954, May 1, 1955, August 31, 1955, April 1, 1956, July 1,