Ameren Services - provides shared administrative support services—everything from accounting to information technology—to Ameren and its operating companies, subsidiaries and affiliates.
AmerenEnergy Fuels & Services - provides fuel and energy-related products and services for Ameren and its affiliated operating companies.
AmerenEnergy Resources - an integrated energy commodity company focused on providing energy solutions to the Midwest market. Parent to two subsidiaries:
Ameren Energy Marketing - the wholesale and retail marketing subsidiary. Sells energy in the wholesale and retail markets throughout the Midwest.