Shareholder Vote · 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): April 27, 2010 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 1-3672 Central Illinois Public Service Company (Illinois Corporation) 607 East Adams Street Springfield, Illinois 62739 (217) 523-3600 37-0211380 1-2732 Central Illinois Light Company (Illinois Corporation) 300 Liberty Street Peoria, Illinois 61602 (309) 677-5271 37-0211050 1-3004 Illinois Power Company (Illinois Corporation) 70 South Main Street Decatur, Illinois 62523 (217) 424-6600 37-0344645 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 5.07 Submission of Matters to a Vote of Security Holders. At the annual meeting of shareholders of each of Ameren Corporation (“Ameren”), Union Electric Company (“Union Electric”), Central Illinois Public Service Company (“CIPS”), Central Illinois Light Company (“CILCO”) and Illinois Power Company (“IP”) held on April 27, 2010 (each, its respective “Annual Meeting”), the matters listed below were submitted to a vote of its respective shareholders. Item (1): Election of Directors Ameren Ameren shareholders elected the 12 nominees named in the definitive proxy statement for the Annual Meeting to serve as directors until Ameren’s next annual meeting of shareholders in 2011 and until their respective successors have been duly elected and qualified. Information as to the vote on each director standing for election is provided below: Name Votes For Votes Against Votes Withheld Broker Non-Votes Stephen F. Brauer 153,893,557 — 5,261,742 37,430,121 Ellen M. Fitzsimmons 153,901,322 — 5,253,977 37,430,121 Walter J. Galvin 148,479,216 — 10,676,083 37,430,121 Gayle P. W. Jackson 153,853,013 — 5,302,286 37,430,121 James C. Johnson 154,425,045 — 4,730,254 37,430,121 Steven H. Lipstein 154,356,721 — 4,798,578 37,430,121 Charles W. Mueller 154,140,242 — 5,015,057 37,430,121 Harvey Saligman 153,322,593 — 5,832,706 37,430,121 Patrick T. Stokes 154,350,642 — 4,804,657 37,430,121 Thomas R. Voss 154,595,062 — 4,560,237 37,430,121 Stephen R. Wilson 153,977,254 — 5,178,045 37,430,121 Jack D. Woodard 154,617,987 — 4,537,312 37,430,121 Union Electric, CIPS, CILCO and IP In connection with the Annual Meeting of each of Union Electric, CIPS, CILCO and IP, each registrant did not solicit proxies from its shareholders and the board of directors of each company as previously reported to the Securities and Exchange Commission was re-elected in its entirety. -2- Item (2): Ratification of the Appointment of Independent Registered Public Accounting Firm for the Fiscal Year Ending December 31, 2010 Ameren shareholders ratified the appointment of PricewaterhouseCoopers LLP as Ameren’s independent registered public accounting firm for the fiscal year ending December 31, 2010 as set forth below: Votes For Votes Against Abstentions Broker Non-Votes 193,246,053 2,222,542 1,116,825 — Item (3): Shareholder Proposal Relating to Report on Callaway Plant Extension of Operating License Ameren shareholders did not approve a shareholder proposal requesting that Ameren prepare a report that discloses Ameren’s evaluation of applying for an extension of the Callaway nuclear power plant operating license as set forth below: Votes For Votes Against Abstentions Broker Non-Votes 10,774,938 135,512,288 12,868,073 37,430,121 Item 8.01 Other Events. At a regularly scheduled meeting of Ameren’s Board held on April 27, 2010, Ameren’s President and Chief Executive Officer, Thomas R. Voss, was elected to the additional position of Board Chairman to succeed Gary L. Rainwater, who retired from Ameren on such date. A copy of a press release regarding this election is filed herewith as Exhibit 99.1. Item 9.01 Financial Statements and Exhibits. (d) Exhibits Exhibit Number Description 99.1 Press Release, dated April 27, 2010. -3- S IGNATURES 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. A MEREN C ORPORATION (Registrant) /s/ Martin J. Lyons, Jr. Martin J. Lyons, Jr. Senior Vice President and Chief Financial Officer U NION E LECTRIC C OMPANY (Registrant) /s/ Martin J. Lyons, Jr. Martin J. Lyons, Jr. Senior Vice President and Chief Financial Officer C ENTRAL I LLINOIS P UBLIC S ERVICE C OMPANY (Registrant) /s/ Martin J. Lyons, Jr. Martin J. Lyons, Jr. Senior Vice President and Chief Financial Officer C ENTRAL I LLINOIS L IGHT C OMPANY (Registrant) /s/ Martin J. Lyons, Jr. Martin J. Lyons, Jr. Senior Vice President and Chief Financial Officer -4- I LLINOIS P OWER C OMPANY (Registrant) /s/ Martin J. Lyons, Jr. Martin J. Lyons, Jr. Senior Vice President and Chief Financial Officer Date: April 30, 2010 -5-