Mr Bennett could be facing up to 20 years in jail

Phillip Bennett was suspended from his post on 10 October and charged two days later with securities fraud.

It is alleged he hid $430m (�243m) in bad debts from Refco shareholders through a series of transactions before the company went public in August.

The delay gives the Department of Justice and Securities and Exchange Commission more time to investigate.

Bid deadline

Federal prosecutors had originally been given a Monday cut-off for getting hold of a grand jury indictment against Mr Bennett.

That deadline has now been delayed, says the US Attorney's Office for the Southern District of New York.

Refco was one of the biggest independent US companies providing liquidity - to ensure traders are able to buy and sell contracts - as recently as two weeks ago.

But on 18 October, a week after charges were levelled against Mr Bennett, the group filed for bankruptcy.

However, its futures brokerage business and other subsidiaries did not enter Chapter 11 protection.

A number of potential suitors have shown interest in acquiring parts of Refco's business, particularly its futures brokerage unit, and formal bids are due on Friday.

Money repaid

Mr Bennett is accused of hiding the fact that Refco Capital Markets - an unregulated subsidiary he controlled - owed $430m to its parent company through a series of undisclosed transactions.

He faces up to 20 years in jail if found guilty of securities fraud.

The $430m has since been repaid but the arrangement was not revealed at the time of Refco's flotation, calling the company's future into question.

Meanwhile, the SEC is also looking closely at the roles played by accountants Grant Thornton, which audited Refco's books, and also at banks which underwrote Refco's $583m share offering in August.