Ameren Illinois Company

Operating as Ameren Illinois, the Ameren Illinois Company is an Illinois-based utility that primarily handles the regulated generation, transmission, and distribution of electricity. Additionally, it oversees natural gas distribution operations. This extensive service provider delivers electricity to approximately 1.2 million customers and natural gas to 800,000 customers, spanning a vast 43,700 square-mile region across central and eastern Illinois. Founded in 1902, the company maintains its headquarters in Collinsville, Illinois. It was previously known as Central Illinois Public Service Company before adopting the Ameren Illinois Company name in October 2010. Ameren Illinois Company operates as a subsidiary of Ameren Corporation.