Santo Maggio, 56, who was president of the Refco Capital Markets unit, pleaded guilty to four counts -- two counts of securities fraud, one count of conspiracy and one count of wire fraud -- at a hearing before Magistrate Judge Ronald Ellis in Manhattan federal court.

Separately, the U.S. Securities and Exchange Commission said in a related action it had settled a civil lawsuit against Maggio.

Refco and 23 affiliates filed for Chapter 11 bankruptcy protection on October 17, 2005, a week after revealing that former Chief Executive Phillip Bennett had hidden $430 million of bad customer debt. It later liquidated its operations.

Maggio told the judge that Refco's losses were covered up.

"I participated with others to hide the true financial health of Refco," he said. "I deeply regret my conduct and the harm that it has caused."

He faces a maximum sentence of 65 years for the charges. He is scheduled to be sentenced on May 9.

The plea comes a day after prosecutors, along with the U.S. Postal Inspection Service and the Securities and Exchange Commission, filed charges against Joseph Collins, a former outside lawyer for Refco.