Confidence in American International Group has grown in the two weeks since Brian Duperreault was appointed chief executive officer.

The giant insurance company’s share price has risen 3.7 per cent, from $61.82 to $64.10, since the Bermuda-born CEO took the helm on May 15.

And last week AM Best’s outlook for the ratings assigned to AIG was declared “stable”, raising investor confidence after the agency had placed the ratings under review for the previous four months.

Darian Ryan, an analyst with AM Best, said the appointment of Mr Duperreault, 70, was a factor in the ratings decision.

Morgan Stanley, billionaire activist investor Carl Ichan, and Hank Greenberg, who was CEO of AIG for 38 years until 2005, all gave immediate support to Mr Duperreault’s appointment.

Morgan Stanley upgraded AIG’s stock to overweight and assigned a price target of $72. For the past two weeks the shares have been steadily rising. The stock currently has an analyst’s target price on Yahoo! Finance of about $69.

Three days after becoming CEO, Mr Duperreault showed his faith in the road ahead for the company when he purchased 80,000 shares for $4.91 million, buying at $61.48 during a brief dip in the stock.

From January to mid-May, AIG shares fell 7 per cent, but since Mr Duperreault’s appointment the stock has recovered a chunk of that loss, boosted by the positive words of support from the likes of Mr Ichan and Mr Greenberg, and improved investor sentiment.