American International Group Inc. named Brian Duperreault, one of the most experienced managers in the property-casualty insurance industry, to be the company's seventh chief executive officer since 2005 and improve results at the operation selling coverage to commercial clients.

Duperreault, who spent time at AIG earlier in his career, will begin his role immediately, the New York-based insurer said Monday in a statement. He is stepping down as CEO of Hamilton Insurance Group and succeeds Peter Hancock, who said in March he would depart AIG amid insufficient support from investors.

The new CEO will seek to bring stability to AIG, which has endured the departure of top executives, higher than expected claims costs and four losses in seven quarters.