American International Group shareholder and former chief executive Maurice "Hank" Greenberg said on Friday he was considering "strategic alternatives" for the world's largest insurer.
Greenberg, ousted by AIG's board in 2005 during an investigation into fraud by then New York attorney general Eliot Spitzer, said in a regulatory filing that he anticipated holding discussions with other shareholders and third parties that would "improve ... the value of their investment."
As of October, Greenberg owned or controlled through his companies more than 300 million shares of AIG, or nearly 12 percent, according to Reuters data.
Greenberg, who has extensive links with Chinese state-owned entities and government officials, said in the filing with the U.S. Securities and Exchange Commission that he and parties involved with him had not yet made any decisions regarding their intentions. The filing named Edward Matthews, a former executive of AIG, and Starr International and C.V. Starr & Co., both of which are controlled by Greenberg.
AIG's shares rose 4.4 percent to $61.77 in after-hours trade after closing at $59.12 on the New York Stock Exchange.
Analysts said Greenberg's efforts could lead to him having a major affect on AIG's future.
"He's a major shareholder, and he has a significant amount of influence, although well short of control," said Donald Light, an analyst at Celent LLC.
Light said Greenberg, 82, could be looking to sell off AIG's non-insurance activities, such as its financial services division, where the company has much of its exposure to securities backed by subprime mortgages that are now a big concern to shareholders.
"It could also be viewed as a way for Greenberg to reassert control over the corporation that he built and was forced out of," said Light.
Light said it was unlikely that Greenberg could take over AIG, which has a market capitalization of more than $150 billion. But he noted that Greenberg has close connections with major Chinese firms.
In addition to insurance, AIG provides asset management and financial services.
Jeff Auxier of Auxier Asset Management, who owns AIG shares, said the company should spin off non-core businesses.
"They are in too many things and there are no synergies," he said. "I would give Greenberg full control of AIG's international operations and spinoff everything else."