We're Ameren Corporation (AEE), a St. Louis-based, Fortune 500 company that powers the quality of life for millions of people ... throughout Illinois and Missouri. Ameren Illinois provides electric distribution and transmission service, as well as natural gas distribution service, while Ameren Missouri provides vertically integrated electric service, with generating capacity of over 10,200 megawatts, and natural gas distribution service. Combined, we serve 2.4 million electric and more than 900,000 natural gas customers in a 64,000 square mile area. We're the largest electric utility in Missouri and the second largest in Illinois, and we're among the nation's largest investor-owned electric or gas utility. read more