0001193125-12-278674 Sample Contracts

THIRD SUPPLEMENTAL INDENTURE Dated as of May 15, 2012

Third Supplemental Indenture • June 21st, 2012 • Ameren Corp • Electric & other services combined • New York

• Contract Type
  Third Supplemental Indenture
• Filed
  June 21st, 2012
• Company
  Ameren Corp
• Industry
  Electric & other services combined
• Jurisdiction
  New York

THIS THIRD SUPPLEMENTAL INDENTURE to the Indenture referred to below is dated as of May 15, 2012 (this “Third Supplemental Indenture”) between AMEREN ILLINOIS COMPANY, an Illinois corporation (the “Company”), and THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A. (formerly The Bank of New York Trust Company, N.A.) (the “Trustee”).

FIRST SUPPLEMENTAL INDENTURE Dated as of May 15, 2012

First Supplemental Indenture • June 21st, 2012 • Ameren Corp • Electric & other services combined • New York

• Contract Type
  First Supplemental Indenture
• Filed
  June 21st, 2012
• Company
  Ameren Corp
• Industry
  Electric & other services combined
• Jurisdiction
  New York

THIS FIRST SUPPLEMENTAL INDENTURE to the Indenture referred to below is dated as of May 15, 2012 (this “First Supplemental Indenture”) between UNION ELECTRIC COMPANY, a Missouri corporation (the “Company”), and THE BANK OF NEW YORK MELLON (formerly The Bank of New York) (the “Trustee”).