Ameren Corporation Issues $400M 5.50% First Mortgage Bonds Due 2036

What Happened
Ameren Corporation (via subsidiary Ameren Illinois Company) announced on August 24, 2026 that Ameren Illinois sold $400 million principal amount of 5.50% First Mortgage Bonds due 2036. The bonds were offered under a Form S-3 registration statement (effective August 4, 2026) and a prospectus supplement dated August 17, 2026. Ameren Illinois received approximately $397.4 million in net offering proceeds, before expenses.

Key Details

• Issuer: Ameren Illinois Company, a subsidiary of Ameren Corporation.
• Amount: $400,000,000 principal amount of First Mortgage Bonds.
• Terms: 5.50% fixed interest rate, maturity in 2036.
• Proceeds & paperwork: Net offering proceeds ~ $397.4M (before expenses); offering under Form S-3 and Prospectus Supplement (Aug 17, 2026). Underwriting agreement dated Aug 17, 2026; supplemental indenture dated Aug 1, 2026 included as exhibits to the 8-K.

Why It Matters
This transaction increases Ameren Illinois’s long-term debt with a fixed-rate bond maturing in 2036 and provides nearly $397.4M in net cash proceeds. For investors, the filing is primarily informative about the company’s financing activity and debt profile; the 8‑K also files related legal and underwriting documents as exhibits. The filing does not specify how the proceeds will be used.