AIG's stock has lost nearly 25% of its value since Feb. 11, just before the company disclosed receiving subpoenas from the SEC and the New York attorney general about its accounting for insurance transactions.

As many as 30 AIG executives were aware of some financial transactions now being investigated by the company, and some of those executives may have been involved in the transactions, said one person familiar with the situation.

It isn't known whether newly installed CEO Martin Sullivan was aware of deals now under scrutiny. But people familiar with the matter said he isn't among the executives who have received subpoenas. Mr. Sullivan declined to comment through an AIG spokesman, and didn't respond to e-mails sent to his AIG account.

For now, AIG's independent directors, the leaders in the internal probe, are focused on fewer than 10 transactions, said people with knowledge of the situation. But that number could grow amid pressure from the SEC to scour the books and uncover any problems, these people said. Dozens of additional transactions have been identified for further review, said two people close to the matter.

AIG's board has hired a law firm to work on its internal probe, while the company has hired a second one. The board also is considering hiring forensic accountants to work on its probe -- a measure the SEC would support.

The transactions under scrutiny involve potential accounting errors of $1.5 billion to $3 billion since 1999, said two people familiar with the situation. The company has told regulators that some of the transactions may need to be reversed, which could affect financial statements by several billion dollars, several other people close to the matter said. AIG hasn't yet determined whether to restate past years' earnings or take a charge against current earnings, according to one person familiar with the matter.

AIG continues to "believe that the matters subject to review are unlikely to result in significant changes to the company's financial position," meaning shareholder's equity, said an AIG spokesman, Chris Winans.

The executive forced out yesterday was Michael Murphy, a longtime confidante of Mr. Greenberg and an expert of tax matters who is based in Bermuda, said two people familiar with the matter. Mr. Murphy worked for American International Co., a Bermuda-based unit of AIG that provides management services to some insurers, a person familiar with the matter said. Records show he also held senior positions at Starr International Co., a private holding company, headed by Mr. Greenberg, that pays deferred compensation to AIG employees, and Bermuda-based Astral Reinsurance Co., another AIG unit.

Calls placed last week to Mr. Murphy at AIG's Bermuda office were transferred to its legal department, but messages left there weren't returned. Mr. Murphy's attorney, Sean O'Shea, yesterday said he had not been informed of his client's dismissal, and did not know whether Mr. Murphy had been notified.

Mr. Sullivan, 50, has worked at AIG since he was a teenager. He is highly regarded internally and long has been a favorite of Mr. Greenberg. The company hopes he can restore stability to AIG.

While discussing Mr. Greenberg's future role at the company, directors also have been considering the historically important, and highly unusual, role played in compensation by Starr International. Created shortly after AIG's initial public offering in 1969, closely held Starr International is run by key AIG executives, including Mr. Greenberg as its chairman. Its board chooses which AIG executives benefit from the compensation plan. As of early last year, the latest date for which figures are available, Starr International owned 11.9% of AIG shares.

The law firms running the probes within AIG are scheduled to brief authorities today, including the SEC, Mr. Spitzer and New York insurance regulators. AIG's internal investigation is being conducted by Paul, Weiss, Rifkind, Wharton & Garrison. It is working as well with Simpson Thacher & Bartlett, a law firm retained by the independent directors.

Some of the transactions under scrutiny by the SEC may have originated more than five years ago, one person familiar with the situation said. While companies generally are liable only for wrongdoing dating back five years, authorities believe some older transactions have played out on financial statements in more recent years.

New York insurance regulators have flagged several large transactions for review, drawing on information culled from AIG's statutory filings in recent years, said people familiar with the matter. The insurance regulators have zeroed in on transactions over the past five years with 13 to 15 offshore entities involved in reinsurance -- which is insurance for insurance companies -- though that number could rise in coming days, these people said. On Friday and Saturday, the SEC and Mr. Spitzer's office also issued a subpoena seeking information about AIG's transactions with offshore entities, including Starr International and a related entity, these people said.

Investigators are trying to determine if AIG secretly controlled some of these entities, these people said. If it did, it means that AIG itself is responsible for some property-casualty policy claims that its financial statements indicate will be covered by an unaffiliated reinsurer, they said.

In particular, AIG directors are trying to determine if shareholders in one off-shore entity held the right to sell their shares to Starr International at a fixed price, the person familiar with the directors' probe said. If so, this is a version of what is known as a "put" option -- the right to sell shares at a set price. If such an arrangement was in place, the offshore entity's shareholders were guaranteed to get their money back, meaning they had no money at risk and wouldn't have been true owners.

Even as the investigators examine AIG's dealings with obscure and often tiny entities in Barbados, Bermuda and the Cayman Islands, its transactions with some insurers in the U.S. beyond General Re also are of keen interest to regulators, said two people familiar with the situation. Still, AIG officials believe the size of any charge or restatement would reduce shareholder's equity by no more than about $830 million, or 1%, people familiar with the matter said on Friday.

AIG also remains "hopeful" that it will make its stated Thursday deadline for filing its annual report to shareholders. "If we miss it, it won't be by much," Mr. Winans, the spokesman, said Friday.

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