-- Troubled commodities broker Refco Inc. filed for Chapter 11 bankruptcy protection and said it reached a preliminary deal to sell its core futures brokerage business to a group of private investors for $768 million.

The consortium of prospective buyers for Refco LLC is led by private buyout firm J.C. Flowers & Co., which specializes in taking distressed financial companies and either turning them around or selling the pieces to other companies.

The investors are purchasing just the commodities business, which remains solvent.

"Part of Refco's appeal is its independence," Flowers said. "It's too early to predict what the future might hold, but the ideal would be for Refco to continue as an independent company and restored to what it was."

The bankruptcy and brokerage sale capped a week of stunning disintegration for Refco, which disclosed Oct. 10 that its former chief executive, Phillip R. Bennett, concealed a $430 million debt from the company's books. Bennett was arrested and charged with securities fraud after repaying the company that amount with interest.

Authorities said the hidden debt was as high as $545 million at one point.

Last week, the company froze customer accounts in Refco Capital Markets Ltd., an offshore broker subsidiary, until next week. And it said Thursday that it would liquidate its Refco Securities LLC subsidiary, which trades stocks, bonds and credit products.

While the company has refused to elaborate on its news releases, customers have abandoned Refco in droves, precipitating a cash crunch that led to the bankruptcy filing. On Tuesday, the Standard & Poor's credit rating service lowered Refco's bond ratings to "D" -- meaning that the bonds are in payment default.

In its bankruptcy filing, Refco listed assets of $48.8 billion and liabilities of $48.6 billion. Just two months ago, Refco had assets of $74.4 billion, according to the prospectus filed with the Securities and Exchange Commission for the company's initial stock offering.

The New York Stock Exchange announced Refco's stock would be delisted as a result of the bankruptcy filing. Shares of Refco, which went public in August, tumbled last week before the Big Board suspended trading on Thursday.

After being delisted Tuesday from the New York Stock Exchange, shares of Refco were trading at just 65 cents each on the Pink Sheets electronic bulletin board -- a 98 percent drop from its closing price on Oct. 7, the last trading day before the accounting scandal came to light.

In its statement late Monday, Refco said Mark Winkelman would be chairman of Refco LLC and Jacob Goldfield would be vice chairman. Winkelman was formerly head of J. Aron & Co. -- investment bank Goldman Sachs's commodities group -- and co-head of Goldman Sachs's fixed income division.

Other members of the Flowers-led consortium include Enstar Group Inc., Silver Point Capital LP, MatlinPatterson Global Advisers LLC and Texas Pacific Group.