Executive Change · Shareholder Vote

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 22, 2013 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 Ameren Illinois Company (Illinois Corporation) 6 Executive Drive Collinsville, Illinois 62234 (618) 343-8039 37-0211380 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 5.02 Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers. (b) On April 22, 2013, Stephen F. Brauer submitted his resignation from the Board of Directors (the “Board”) of Ameren Corporation (“Ameren” or the “Company”), effective immediately, and informed the Company that he did not wish to be considered for election to the Board at the Company’s annual meeting of shareholders held on April 23, 2013. Mr. Brauer’s resignation as a director and decision to withdraw from consideration for election to the Board was due to business commitments and not due to any disagreements with the Company on any matter relating to the Company’s operations, policies or practices. Item 5.07 Submission of Matters to a Vote of Security Holders. At the annual meeting of shareholders of each of Ameren, Union Electric Company d/b/a Ameren Missouri (“Ameren Missouri”) and Ameren Illinois Company d/b/a Ameren Illinois (“Ameren Illinois”) held on April 23, 2013 (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 following ten nominees, each of whom was named in Ameren’s definitive proxy statement relating to the Annual Meeting, to serve as directors until Ameren’s next annual meeting of shareholders in 2014 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 Withheld Abstentions Broker Non-Votes Catherine S. Brune 157,908,419 2,401,892 — 38,560,295 Ellen M. Fitzsimmons 157,997,688 2,312,623 — 38,560,295 Walter J. Galvin 157,911,078 2,399,233 — 38,560,295 Gayle P.W. Jackson 157,891,117 2,419,194 — 38,560,295 James C. Johnson 137,568,311 22,742,000 — 38,560,295 Steven H. Lipstein 155,020,988 5,289,323 — 38,560,295 Patrick T. Stokes 154,807,474 5,502,837 — 38,560,295 Thomas R. Voss 152,639,477 7,670,834 — 38,560,295 Stephen R. Wilson 155,319,258 4,991,053 — 38,560,295 Jack D. Woodard 155,000,831 5,309,480 — 38,560,295 -2- Ameren Missouri At Ameren Missouri’s annual meeting of shareholders held on April 23, 2013, the following individuals (comprising Ameren Missouri’s full Board of Directors) were elected to serve until the next annual meeting of shareholders in 2014 and until their respective successors have been duly elected and qualified: Warner L. Baxter, Daniel F. Cole, Adam C. Heflin, Martin J. Lyons, Jr., Michael L. Moehn, Charles D. Naslund and Gregory L. Nelson. Each individual received 102,123,834 votes for election and no withheld votes, abstentions or broker non-votes. Ameren Illinois At Ameren Illinois’ annual meeting of shareholders held on April 23, 2013, the following individuals (comprising Ameren Illinois’ full Board of Directors) were elected to serve until the next annual meeting of shareholders in 2014 and until their respective successors have been duly elected and qualified: Daniel F. Cole, Martin J. Lyons, Jr., Richard J. Mark and Gregory L. Nelson. Each individual received 25,452,373 votes for election and no withheld votes, abstentions or broker non-votes. Item (2): Advisory Approval of Executive Compensation Ameren shareholders approved, on an advisory basis, the compensation of certain executives as disclosed in the Compensation Discussion and Analysis, the compensation tables and other narrative executive compensation disclosures in the definitive proxy statement relating to the Annual Meeting, as set forth below: Votes For Votes Against Abstentions Broker Non-Votes 139,118,205 17,791,401 3,400,705 38,560,295 Item (3): Ratification of the Appointment of Independent Registered Public Accounting Firm for the Fiscal Year Ending December 31, 2013 Ameren shareholders ratified the appointment of PricewaterhouseCoopers LLP as Ameren’s independent registered public accounting firm for the fiscal year ending December 31, 2013, as set forth below: Votes For Votes Against Abstentions Broker Non-Votes 194,118,904 3,629,773 1,121,929 — Item (4): Shareholder Proposal Relating to Report on Reducing Risk in Energy Portfolio Through Increased Energy Efficiency and Renewable Energy Resources Ameren shareholders did not approve a shareholder proposal requesting a report, to be reviewed by a Board committee comprised of independent Ameren directors, on actions the -3- Company is taking or could take to reduce risk throughout its energy portfolio by diversifying the Company’s energy resources to include increased energy efficiency and renewable energy resources, as described in the definitive proxy statement relating to the Annual Meeting, as set forth below: Votes For Votes Against Abstentions Broker Non-Votes 14,646,481 117,957,546 27,706,284 38,560,295 -4- 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/ Gregory L. Nelson Gregory L. Nelson Senior Vice President, General Counsel and Secretary U NION E LECTRIC C OMPANY (Registrant) /s/ Gregory L. Nelson Gregory L. Nelson Senior Vice President, General Counsel and Secretary A MEREN I LLINOIS C OMPANY (Registrant) /s/ Gregory L. Nelson Gregory L. Nelson Senior Vice President, General Counsel and Secretary Date: April 23, 2013 -5-