The complaint seeks a permanent injunction and civil penalties against Mr. Bennett, as well as the surrender of ill-gotten gains. A lawyer for Mr. Bennett did not immediately return a phone call seeking comment on Tuesday.

Late Friday, Mr. Bennett, 59, pleaded guilty to a 20-count criminal indictment, including charges of conspiracy, securities fraud, bank fraud and making false filings with the S.E.C. Mr. Bennett, a British citizen, faces life in prison on the criminal charges under federal sentencing guidelines.

In his guilty plea last week, he admitted to concealing the fraud from the company’s auditors and investors and from the buyout firm Thomas H. Lee Partners, which bought a stake in Refco in 2004 and has been sued on accusations that it did not follow up on red flags at the company.

Mr. Bennett has been free on $50 million bail since shortly after his arrest in 2005 and is restricted to his home in New Jersey, where he is subject to electronic monitoring.

Refco sought bankruptcy protection in 2005, soon after the company announced it had discovered $430 million in debt owed to a private entity controlled by Mr. Bennett.

Mr. Bennett was expected to go to trial on the criminal charges next month, along with two other former Refco executives, Robert C. Trosten and Tone N. Grant. Prosecutors said last week that they intended to proceed with the trial against Mr. Trosten, who was chief financial officer, and Mr. Grant, the former president. Both have denied wrongdoing.

Joseph P. Collins, a longtime lawyer for Refco, also is separately facing criminal charges in the matter.

Santo C. Maggio, Refco’s former executive vice president, pleaded guilty to criminal charges in December and agreed to forfeit $23 million. Mr. Maggio, who has long been cooperating with prosecutors, is expected to testify at any criminal trials in the matter.