Refco's filing is fourth-largest US bankruptcy

Refco Inc., the futures broker under investigation for hiding a $430 million debt, filed for court protection from creditors in the fourth-largest US bankruptcy.

Shares of Refco plunged, wiping out about $924 million in market value, after the company asked a US bankruptcy court in Manhattan for permission to reorganize its $48.6 billion in liabilities.

In the filing, New York-based Refco left out the units it plans to sell to a buyout group led by J.C. Flowers & Co. for $768 million.

Refco's collapse comes 10 weeks after it sold shares to the public for the first time, and may set up a contest between the Flowers group and the government of Dubai, whose offers to purchase the whole company have been rebuffed.

Refco listed assets of $48.8 billion in its filing, which included the parent company and 23 of its units.

The company's 127.5 million shares, which were delisted from the New York Stock Exchange, resumed trading under the symbol RFXCQ and fell $7.25 to 65 cents in over-the-counter trading yesterday.