ST. LOUIS, Sept. 15, 2025 /PRNewswire/ -- Ameren Illinois Company, a subsidiary of Ameren Corporation (NYSE:AEE), announced today the pricing of a public offering of $350 million aggregate principal amount of 5.625% first mortgage bonds due 2055 at 103.196% of their principal amount, with a re-offer yield of 5.405%. The first mortgage bonds will be a further issuance of Ameren Illinois' 5.625% first mortgage bonds due 2055 issued on March 3, 2025, in the principal amount of $350 million. The transaction is expected to close on September 26, 2025, subject to the satisfaction of customary closing conditions.

Ameren Illinois intends to use the net proceeds of the offering to repay a portion of its short-term debt.

KeyBanc Capital Markets Inc., TD Securities (USA) LLC, U.S. Bancorp Investments, Inc. and Fifth Third Securities, Inc. are acting as joint book-running managers for the offering.

The offering is being made only by means of a prospectus and related prospectus supplement. A prospectus supplement related to the offering will be filed with the Securities and Exchange Commission. Copies of the prospectus and related prospectus supplement for the offering, when available, may be obtained via the Securities and Exchange Commission's website at www.sec.gov or by contacting U.S. Bancorp Investments, Inc., 214 N. Tryon Street, 26th Floor, Charlotte, North Carolina 28202, Attn: Investment Grade Syndicate, phone: 1-877-558-2607. This press release does not constitute an offer to sell or a solicitation of an offer to buy the first mortgage bonds and shall not constitute an offer, solicitation or sale in any jurisdiction in which, or to any person to whom, such an offer, solicitation or sale is unlawful.

About Ameren Illinois

Ameren Illinois delivers energy to 1.2 million electric and more than 800,000 natural gas customers throughout central and southern Illinois. Our service territory covers more than 1,200 communities and 43,700 square miles and our mission is to power the quality of life. For more information, visit Ameren.com/Illinois or follow us on X at @AmerenIllinois or Facebook.com/AmerenIllinois.

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SOURCE Ameren Illinois