Berkshire Hathaway announced that its subsidiary, General Re Corp., terminated the consulting services of Ronald E. Ferguson, its former chief executive officer, after he refused to answer questions from investigators.

The Omaha-based firm said on its Web site on May 20 that the move came after Mr. Ferguson invoked the Fifth Amendment in response to questions from the Securities and Exchange Commission and the Department of Justice relating to ongoing investigations.

Gen Re has been under scrutiny for a finite reinsurance transaction involving American International Group. AIG admitted the accounting of the deal was improper, prior to being hit with a civil lawsuit last Thursday filed jointly by New York Attorney General Eliot Spitzer and the New York Insurance Department. The suit also alleged improper accounting practices.