Robert C. Trosten, the former chief financial officer of Refco Inc.,has been indicted on securities fraud and other charges that he helped ex-Chief Executive Phillip R. Bennett hide hundreds of millions of dollars in trading losses by Refco and its customers from the investing public, prosecutors said Tuesday.

In a press release, the U.S. Attorney’s office in Manhattan said that Mr. Trosten, 57 years old, has been charged with conspiracy, securities fraud and two counts of wire fraud in a new indictment issued Tuesday.

He faces up to 20 years in prison on the most serious charges of securities fraud and wire fraud. Mr. Trosten served as Refco’s financial chief from May 2000 to August 2004, according to court documents.

The new indictment also adds an additional count of securities fraud and two new counts of wire fraud against Mr. Bennett related to allegations of fraud against the company’s bond holders.

Mr. Bennett and Mr. Trosten, of Gladstone, N.J., are expected to be arraigned on the charges at a hearing in federal court in Manhattan on Wednesday.

Prosecutors have alleged that Mr. Bennett, with Mr. Trosten’s help, sought to hide from Refco’s auditors and investors hundreds of millions of dollars in trading losses sustained by the company and by customers trading through its accounts.

The government claims that Mr. Bennett and Mr. Trosten transferred those losses to a separate company Mr. Bennett controlled, directed a series of transactions to conceal them and caused the company to make false filings with securities regulators.

The scheme to hide the losses resulted in the August 2004 leveraged buyout of Refco by Thomas H. Lee Partners, which was financed in part by about $600 million in notes issued by Refco that were sold based on false financial statements, and the August 2005 initial public offering of Refco stock, in which the public purchased approximately $583 million of Refco common stock based on a false and fraudulent registration statement, prosecutors said.