Carl Icahn, the activist investor calling for a breakup of American International Group Inc., said the alternative plan presented last week by the insurer’s chief executive officer was inadequate and that he’s assembling a slate of directors to shake up the company.

Icahn plans to propose a list of possible board members by the end of next week, he said in a phone interview Monday, without identifying candidates.

CEO Peter Hancock has rebuffed Icahn’s call to split AIG into separate insurers focusing on life, property-casualty and mortgage coverage. The CEO outlined plans last week for a more patient approach of simplifying the company, saying he’d have an initial public offering of a partial stake in the mortgage guaranty business, sell a broker-dealer operation and consider divestitures of other assets. Hancock said last week that “there are important tax and diversification reasons that would preclude major divestitures in the short term.”

Sid Sankaran, who has been designated to be the insurer’s next chief financial officer, said in a video posted online Monday prior to Icahn’s remarks that breaking up the company would punish investors by jeopardizing tax assets. AIG accumulated deferred tax assets when the insurer was was unprofitable, and the holdings can limit future obligations to the government.

The insurer pared losses after Icahn’s remarks, changing hands for $56.29 at 4:15 p.m. in New York, a decline of 0.3 percent from Friday’s close. That stock traded for as low as $55.38 earlier Monday.

AIG investors last year endorsed the company’s nominees to the board by wide margins. All 13 directors supported by the insurer got at least 900 million votes for one-year terms, including Hancock and Doug Steenland, who is now the chairman. None of the candidates faced more than 90 million “against” votes.

Chairman’s View

Steenland on Monday reiterated his support for Hancock’s plan, announced last week, to return $25 billion to shareholders over the next two years. Profits from operating units and tax benefits will contribute as much as $10 billion of that sum, AIG said in a slide show. Proceeds from divestitures, reinsurance deals and reduced leverage are also expected to free up capital.

“Our board of directors and management are fully aligned behind the strategy outlined on Jan. 26,” Steenland said Monday in a statement. “We look forward to continued discussions with our shareholders on the strategy we have advanced.”

–With assistance from Katherine Chiglinsky.