The turnaround expert who led Enron Corp. through its bankruptcy engaged in unacceptable billing practices and has agreed to cut in half the $25 million he has been seeking as a “success fee,” the Justice Department said Monday.

The department’s U.S. Trustee Program, which monitors the administration of bankruptcy cases, said it uncovered the billing problems after Stephen Forbes Cooper LLC and its principal, Stephen Cooper, asked the U.S. Bankruptcy Court in New York for $25 million as the fee for guiding the one-time energy giant, decimated by scandal, through its Chapter 11 case.