General RE Corp. chief executive Joseph Brandon has resigned a week after a report that federal prosecutors have been pressuring corporate parent Berkshire Hathaway Inc. to replace him.

Brandon's departure, effective immediately comes after four executives at the reinsurer were convicted of fraud in February. They were found guilty of engaging in a sham deal to deceive investors of insurer American International Group. Brandon had been named an unindicted co-conspirator in the case. He was not charged with a crime.

Last week, the Wall Street Journal reported that U.S. prosecutors had been pressing Omaha, Nebraska-based Berkshire Hathaway to replace Brandon as part of a move to end the government's investigation of General Re.

Berkshire Hathaway said Brandon would be replaced by Franklin Montross, the current President of General Re.