The brokerage arm of the world's largest publicly traded hedge-fund manager, Man Group PLC, won the auction to buy the assets of bankrupt futures broker Refco Inc., which collapsed last month after revelations that its chief executive had allegedly hid $430 million in bad debts.

In winning Refco's assets -- including its customers, technology and employees -- Man Financial trumped competing offers from three other bidders during an auction that began Wednesday and stretched through the night. Another bidder was disqualified because it wanted to buy only part of Refco's assets.

The auction, which was being challenged Thursday afternoon by a group of Refco's creditors, still needed to be approved by a U.S. bankruptcy-court judge.

Refco said it aimed to close the sale within days.

In a statement Thursday, London-based Man said the deal equated to a total consideration of $323 million for "all of Refco's employees and the business of Refco's regulated futures brokerage in the U.S., London, Asia and Canada."

In the same statement, Man chief executive Stanley Fink said the deal would be "value enhancing" for the overall company.

The agreement is significantly below earlier estimates that Refco's assets could fetch as much as $1 billion. However, the amount excludes from the deal $750 million in regulatory capital at Refco, according to a person familiar with the situation. Refco was required to hold this money against its customer accounts much the same way a bank has to keep reserves for deposits it holds.

Because Man won't take the regulatory capital, Refco's receiver will have access to the cash and may be able to use it to help pay the group's creditors, this person said. It wasn't clear, though, how Man Financial would provide regulatory capital against the Refco accounts it assumes; Man Group has surplus regulatory capital on its balance sheet that it may be able to use for this purpose.

Man also cautioned in its statement that the consideration "is subject to possible downward adjustment" depending on the levels of customer funds at closing.

Man said the "purchase price consists of $282 million in cash, the assumption of an estimated $37 million of liabilities and other consideration valued for the purposes of the auction at $4 million." The value of the tangible Refco assets acquired was about $115 million, Man said, mostly derived from the market value of exchange seats held by Refco. The purchase is expected to add to Man's earnings, excluding integration costs, in the financial year starting in April 2007, according to the statement.

The lower-than-expected price of the deal could indicate that the gains to Man Financial may be less than some analysts had initially expected.

Based on the number of futures contracts Refco appeared to trade on an annual basis, it appeared the combination of the two businesses could potentially have doubled the trading handled by Man Financial.

Although Refco's business has undoubtedly shrunk, even a unit doing half its old business could add about 50 percent to the $171 million in pre-tax profit Man Financial is forecast to generate in the fiscal year ending March 31, 2006, said Huw van Steenis, an analyst at Morgan Stanley in London. That would be before potential gains from cost synergies, so the deal could pay for itself in three to four years, he said.