Ameren | 82,955 followers on LinkedIn. 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.