Ameren Illinois Company 

Ameren Illinois Company, an Illinois-based corporation, operates as a subsidiary of Ameren Corporation. It is responsible for the rate-regulated transmission and distribution of electricity and natural gas across the state of Illinois. Its operations are divided into three core segments: Ameren Illinois Electric Distribution: Focuses on the electric distribution activities within Ameren Illinois. Ameren Illinois Natural Gas: Manages the natural gas business for Ameren Illinois. Ameren Illinois Transmission: Primarily encompasses the combined electric transmission operations of both Ameren Illinois and ATXI. Significantly, the vast majority of its revenue is derived from the Ameren Illinois Electric Distribution segment.