Ameren Illinois names CEO to replace Cisel

St. LOUIS (AP) - Ameren Illinois CEO Scott Cisel has left the company and has been replaced by another Ameren executive, Richard Mark.

Ameren Illinois said Wednesday that Cisel stepped down as CEO, president and chairman. The company didn't give details of his departure. A news release says he left to pursue other interests.

Mark has been Ameren Missouri's senior vice president for customer operations.

Ameren Illinois is the dominant electricity and natural gas utility in central and southern Illinois. St. Louis-based Ameren Corp. owns both Ameren Missouri and Ameren Illinois.

Cisel had been CEO since 2005 and began his career as a meter reader.