(Reuters) - American International Group Inc (>> American International Group Inc) said Peter Hancock would succeed Robert Benmosche as chief executive and president, effective Sept. 1.

Hancock joined AIG in 2010 and has headed the company's property-casualty business since March 2011.

Before joining AIG, he was vice chairman of KeyCorp (>> KeyCorp) and a former chief financial officer at JPMorgan Chase & Co (>> JPMorgan Chase & Co.).

The Wall Street Journal reported in May that Hancock and Jay Wintrob, who leads AIG's life-insurance and retirement business, would be the leading candidates for the CEO post after Benmosche retired in September.

BMO Capital Markets analyst Charles Sebaski said Hancock's banking experience would help AIG deal with SIFI (systemically important financial institutions) and the U.S. government, and his appointment "should provide no hiccups to the company."

Sebaski, who has a five-star rating on StarMine due to the accuracy of his estimates, also identified AIG's property-casualty business as needing "more corrective action" and said Hancock's experience in this area would be "probably beneficial" for the company.

BENMOSCHE LEGACY

Retiring CEO Benmosche, who has been with AIG since 2009, is credited with steering the company through the financial crisis. During his tenure, AIG fully repaid the $182.3 billion government bailout it received in 2008 to stave off bankruptcy.

Benmosche, who was diagnosed with cancer in late 2010, was CEO of MetLife Inc (>> Metlife Inc) from 1998 to 2006.

He initially planned to retire from AIG in 2012, but later expressed his desire to carry on.

Soon after becoming the fourth person to hold the CEO post at AIG since June 2008, Benmosche reversed course on the company's strategy in an attempt to turn around its fortunes.

He stopped the sales of assets at throwaway prices, tried to boost employee morale and took on AIG's critics, including government officials.

Sebaski said that under Benmosche's leadership, AIG had moved from "great uncertainty" in 2009 to re-establish itself as a market leader in its core businesses.

In February, AIG raised its quarterly dividend by 25 percent, to 12.5 cents per share.

With Benmosche at the helm, the insurer's stock has more than doubled to Tuesday's close of $55.01 on the New York Stock Exchange.

Benmosche will now take up an advisory role at AIG, the company said in a statement.

(Reporting by Avik Das in Bangalore; Additional reporting by Luciana Lopez in New York; Editing by Simon Jennings)

By Avik Das