Jon Corzine's aggressive bets on European sovereign debt while head of the MF Global Holdings Ltd brokerage led to the firm's dramatic collapse in 2011, according to a report by the bankruptcy trustee.

Former FBI director Louis Freeh acknowledged that a slow U.S. economic recovery had played a role in MF Global's woes, but he said "negligent conduct" contributed to the company's failure.

"The risky business strategy engineered and executed by Corzine and other officers and their failure to improve the company's inadequate systems and procedures so that the company could accommodate that business strategy contributed to the company's collapse," said the 124-page report.

(Reporting by Tom Hals in Wilmington, Delaware; Editing by Gerald E. McCormick)