Company Update

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, 2021       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 1-3672 Ameren Illinois Company ( Illinois Corporation) 10 Executive Drive Collinsville , Illinois 62234 ( 618 ) 343-8150 37-0211380   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 ¨ Ameren Illinois Company ¨   If 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 ¨ Ameren Illinois Company ¨       Co-Registrant Entity Central Index Key 0000018654            ITEM 8.01 Other Events.   On June 29, 2021, Ameren Illinois Company (“Ameren Illinois”), a subsidiary of Ameren Corporation, sold $100 million principal amount of its 0.375% First Mortgage Bonds due 2023 (the “2023 Bonds”) and $350 million principal amount of its 2.90% First Mortgage Bonds due 2051 (the “2051 Bonds” and together with the 2023 Bonds, the “Bonds”). The Bonds were offered pursuant to a Registration Statement on Form S-3 (File No. 333-249475-02), which became effective on October 14, 2020, a Prospectus Supplement dated June 22, 2021 to a Prospectus dated October 14, 2020 relating to the 2023 Bonds and a Prospectus Supplement dated June 22, 2021 to a Prospectus dated October 14, 2020 relating to the 2051 Bonds. Ameren Illinois received aggregate net offering proceeds of approximately $445.2 million, before expenses, upon closing of the transactions.   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   1.1 Underwriting Agreement relating to the 2023 Bonds, dated June 22, 2021, between Ameren Illinois and the several underwriters named therein, for whom RBC Capital Markets, LLC, TD Securities (USA) LLC, Truist Securities, Inc. and Wells Fargo Securities, LLC are acting as representatives.   1.2 Underwriting Agreement relating to the 2051 Bonds, dated June 22, 2021, between Ameren Illinois and the several underwriters named therein, for whom RBC Capital Markets, LLC, TD Securities (USA) LLC, Truist Securities, Inc. and Wells Fargo Securities, LLC are acting as representatives.   4.1* General Mortgage Indenture and Deed of Trust, dated as of November 1, 1992, from Ameren Illinois to The Bank of New York Mellon Trust Company, N.A., as successor trustee (1992 Form 10-K, Exhibit 4(cc), File No. 1-3004).   4.2 Supplemental Indenture, dated as of June 1, 2021, by and between Ameren Illinois and The Bank of New York Mellon Trust Company, N.A., as successor trustee, relating to the 2023 Bonds and the 2051 Bonds.   5.1 Opinion of Craig W. Stensland, Esq., Senior Corporate Counsel, Ameren Services Company, 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 Ameren Illinois 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 thereunto 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/ Michael L. Moehn   Name: Michael L. Moehn   Title: Executive Vice President and Chief Financial Officer        AMEREN ILLINOIS COMPANY   (Registrant)       By: /s/ Richard J. Mark   Name: Richard J. Mark   Title: Chairman and President   Date: June 29, 2021   - 3 -