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): October 21, 2011 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 registrant 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)) ITEM 8.01 Other Events. Reference is made to Overview and Outlook under Part I, Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations in the Form 10-Q for the quarterly period ended June 30, 2011, of registrant Ameren Corporation (“Ameren”) and its registrant subsidiary, Union Electric Company, doing business as Ameren Missouri (“Ameren Missouri”), for a discussion of Ameren’s plans to take actions to align its overall spending to be consistent with regulatory outcomes and economic conditions. On October 21, 2011, Ameren announced that, as part of its efforts to reduce its operations and maintenance expenses, it is extending a voluntary separation offer to approximately 715 management and labor union-represented employees who are 58 years of age or older as of December 31, 2011. This program is being offered to eligible employees at Ameren Missouri and at Ameren Services Company. Employees who accept the separation offer will receive benefits consistent with Ameren’s standard management severance benefits. Employees must decide whether to accept the separation offer by December 22, 2011, and those accepting are expected to leave their employment by December 31, 2011. 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 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) /s/ Martin J. Lyons, Jr. Martin J. Lyons, Jr. Senior Vice President and Chief Financial Officer UNION ELECTRIC COMPANY (Registrant) /s/ Warner L. Baxter Warner L. Baxter Chairman, President and Chief Executive Officer Date: October 21, 2011 - 3 -