Richard Mark

(via Ameren Illinois)

Ameren Illinois has a new Chairman, President and CEO. Effective immediately, Richard Mark, 57, replaces Scott Cisel, who has "left the company to pursue other interests."

The move is an internal one for Ameren, as Mark jumps over the Mississippi from his former post as senior vice president of customer operations for Ameren Missouri. He's been with the company since 2002.

Shifting into Mark's old spot is Michael Moehn, who will leave a similar post at Ameren Illinois.