NEW YORK (Bloomberg) ? Maurice (Hank) Greenberg, who was ousted as chief executive of American International Group Inc. amid an accounting probe, accused the insurer of making ?vile accusations? that are ?impugning? his integrity.

In a letter to AIG?s board dated Wednesday, Greenberg criticised the company for a May 1 statement that former senior managers ordered changes to the insurer?s books, circumventing internal controls. New York-based AIG said accounting errors on reinsurance and investments helped inflate its net worth by $2.7 billion, requiring corrections to five years of results.

?To have all of the accomplishments of my management team despoiled by judgments seemingly based upon incomplete facts is exceedingly disturbing,? Greenberg, 80, said in the letter. ?I have known many of you for a long time and am puzzled by your refusal to share information with me to permit me to respond to the vile accusations made against me.?

Greenberg is fighting back as federal and state investigators examine his role in AIG?s accounting errors. New York Attorney General Eliot Spitzer said last month he may pursue a civil or criminal case against Greenberg and on Wednesday the Federal Bureau of Investigation said it?s begun probing whether cases like AIG?s may be pervasive in the industry.

AIG spokesman Chris Winans confirmed today that the letter was received and declined to comment further. Howard Opinsky, a spokesman for Greenberg?s attorneys, declined to comment beyond distributing a copy of the letter.

AIG wouldn?t identify the former managers it cited in the May 1 statement. Greenberg and former chief financial officer Howard Smith, who was fired in March for failing to cooperate with the probe, are among them, the Wall Street Journal earlier reported, citing unidentified people familiar with the matter. The Journal also earlier reported the letter.

Spitzer told ABC on April 10 that Greenberg, head of AIG for almost 40 years, ran the company with ?an iron fist? and ?did not tell the public the truth?. That may merit civil or criminal prosecution, he said.

Greenberg told board members in the letter that they should have sought Smith?s input before judging the accounting.

?How a conclusion can be reached that unsupported `top level? adjustments allegedly were made, without soliciting information on this subject from the prior chief financial officer or his counsel is beyond my comprehension,? Greenberg wrote in the letter. Smith?s attorney, Andrew Lawler, didn?t return a message left with an assistant.

Shares of AIG fell 45 cents to $53.92 yesterday in New York Stock Exchange composite trading. The stock has fallen 26 percent since the company announced the subpoenas on February 14.

AIG said on May 1 that auditor PricewaterhouseCoopers LLC would issue an ?adverse opinion? on the insurer?s internal controls after the former managers were found to have skirted systems. Greenberg?s attorneys have said PricewaterhouseCoopers gave AIG?s audit committee a report on internal controls in February and noted ?no material exceptions.?

?I was surprised that this press release provided no factual basis to explain why AIG or PricewaterhouseCoopers changed its position,? Greenberg said in the letter.

?It is clear that the restatement entails hindsight analysis about complicated accounting issues which were originally made on a good faith basis both by management (former and present) and AIG?s auditors without objections or inquiry from the board or any member of the board.?

AIG?s non-executive board members include William Cohen, a former US Defence Secretary, Richard Holbrooke, former ambassador to the United Nations, Martin Feldstein, and former chief economic adviser to President Ronald Reagan, and Stephen Hammerman, former general counsel to Merrill Lynch & Co.

The four didn?t return phone calls, nor did Marshall Cohen, George Miles, Ellen Futter, Carla Hills or Frank Zarb, who replaced Greenberg as interim chairman. Bernard Aidinoff and Morris Offit declined to comment. Board member Chia Pei-Yuan couldn?t be reached.

AIG plans to file a 2004 annual report and restate prior years by May 31 after two earlier delays. The company said it expects PricewaterhouseCoopers to sign off on the new numbers.

Spitzer and the Securities and Exchange Commission are investigating instances when a type of reinsurance known as finite, or non-traditional, reinsurance, really amounts to loans, allowing insurers to mask losses even though little or no risk is transferred.

AIG?s internal review began with reinsurance transactions and expanded to uncover misleading or improper booking of asset writedowns, hedge-fund proceeds and underwriting results.

The $2.7 billion of errors represents about 3.3 percent of the company?s book value.

Some of the improper accounting inflated AIG?s book value and net income, while other transactions pumped up the company?s profit from operations, the measure of income most used by Wall Street analysts.

Greenberg invoked his Fifth Amendment right to avoid self- incrimination when he refused to answer questions from investigators April 12.

Greenberg in the letter listed himself as president and chief executive officer of C.V. Starr & Co., an insurance brokerage he controls that has done business with AIG. The letterhead listed C.V. Starr?s address as 70 Pine Street in New York, AIG?s headquarters. Greenberg is looking at office space in Manhattan to relocate C.V. Starr, said spokesman Opinsky.

The former CEO also controls the Starr Foundation and Starr International Co., which is AIG?s largest shareholder and has paid hundreds of millions of dollars in compensation to AIG executives over more than three decades.