Bailed-out insurer American International Group
AIG CEO Bob Benmosche has been in treatment for cancer since late 2010. Chairman Steve Miller was to become interim CEO if Benmosche were unable to continue with the job.
But on Tuesday, business plane maker Hawker Beechcraft named turnaround expert Miller its chief executive, effective immediately.
The board has an active succession planning process and will be assessing its plans in light of Mr. Miller's announcement, AIG said in a statement, adding that he will remain chairman of the board.
AIG's succession plan was a hot topic in late 2010 and early 2011 as the company tried to execute a recovery plan following its $182 billion government rescue. Benmosche has been widely acknowledged as key to that plan.
But he has remained in good health and has indicated a desire to remain with the company and in the job, making succession less of an issue.
Miller is one of the most heralded turnaround experts in the country, having led companies like Delphi Corp, Bethlehem Steel and Waste Management in recent decades.
AIG shares fell 8 cents to $26.72 in afternoon trading. The stock lost half its value last year but has rebounded sharply in 2012. Even so, it remains roughly $2 below the U.S. Treasury's break-even point on its 77 percent stake in the company.
(Reporting By Ben Berkowitz; editing by Mark Porter)