MAURICE “Hank” Greenberg, the former chairman and chief executive of AIG, will today invoke his Fifth Amendment right to silence when he is questioned by regulators over a $500 million transaction that forced him to resign from the world’s biggest insurer.

The decision comes after Eliot Spitzer rebuffed requests by Mr Greenberg’s lawyers to delay the deposition, his lawyers said yesterday.

David Boies, Mr Greenberg’s lead lawyer, said Mr Greenberg was not given access to documents relating to the transactions in question. He also said that the sheer volume of transactions done, some up to 20 years ago, meant it was impossible for Mr Greenberg to have prepared his testimony in time.

In a statement, Mr Greenberg sought to distance himself from a $500 million transaction between AIG and General Re which investigators believe he initiated, by saying that he was “familiar with many, but certainly not all, or even a significant percentage of, the literally millions of transactions each year in approximately 130 countries” undertaken by AIG.

Warren Buffett, the billionaire investor and chief executive of General Re’s parent Berkshire Hathaway, told investigators from Mr Spitzer’s office, the US Securities and Exchange Commission and the Department of Justice yesterday that he knew few details about the transaction.

Mr Buffett, the world’s second-richest man, entered the Woolworth Building on Broadway through a service entrance shielded from the press by a security guard.

The deal allowed AIG to bolster its reserves — a critical gauge of an insurance company’s solvency and strength. However, the authorities have made it clear that Mr Buffett, 74, is a witness and not a target in the investigation. “The focus is AIG and Mr Greenberg, not Warren Buffett,” Mr Spitzer said in a television interview at the weekend.

Mr Spitzer said in the television interview: “These are very serious offences, over a billion dollars of accounting frauds that AIG has already acknowledged. That company was a black box, run with an iron fist by a CEO who did not tell the public the truth.” AIG has been forced to revise down its earning by about $1.7 billion.

Mr Spitzer’s office has said that Mr Buffett has already helped to provide regulators with evidence in the case against AIG. He said regulators had not uncovered any evidence against Mr Buffett.

Last month AIG fired two executives who refused to co-operate with investigations by pleading the Fifth Amendment.

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