Prosecutors plan to call billionaire Warren Buffett as a witness in the criminal trial of five senior insurance executives in the US.

Mr Buffett, CEO of major investment company Berkshire Hathaway and owner of General Re, is expected to give evidence in fraud hearings that stem from a transaction in 2000 involving former executives of AIG and General Re.

Prosecutors allege the five tried to attract investors through the use of $US500 million ($570 million) in inflated loss reserves, added to AIG books in a series of fraudulent transactions.

The former Gen Re officers facing charges are CEO Ronald Ferguson, CFO Elizabeth Monrad, Assistant General Counsel Robert Graham and Senior Vice President and Chief Underwriter Christopher Garand.

The AIG defendant is former Vice President for Reinsurance Christopher Milton.

Mr Buffett has said he did not know the deals were improper and has not been charged.

The trial is scheduled to begin on January 7 in Hartford, Connecticut.

The prosecution also plans to call John Houldsworth, the head of a former subsidiary of Gen Re, and former Gen Re Vice President Richard Napier. Both men pleaded guilty to charges in 2005.

The court will also hear from several high-ranking AIG officials, including director and former board Chairman Frank Zarb.

The executives’ action allegedly cost AIG $US1.64 billion ($1.87 billion), which it agreed to pay last year to settle claims involving the use of deceptive accounting measures.