Former Enron Corp. chief financial officer Andrew Fastow, whose off the books deals led to the high flying energy giant's destruction, faces a federal judge on Tuesday to find out how long he will spend in prison.

Fastow, 44, agreed to forfeit $23.8 million (12.6 million pounds) and serve up to 10 years in prison when he pleaded guilty to participating in fraud that led to Enron's bankruptcy in 2001.

Enron was ranked No. 7 on the Fortune 500 list of companies before revelations of the off balance sheet entities, overseen by Fastow and used to inflate earnings and hide debt, triggered its downfall.

The collapse cost investors billions of dollars and forced thousands of employees to forfeit their jobs and retirement savings.

Many, including former Chairman Kenneth Lay and former Chief Executive Jeff Skilling, blamed Fastow, who admitted stealing from the company as well as defrauding shareholders.

Fastow's testimony helped convict Lay, who died in July before he could be sentenced, and Skilling, scheduled to be sentenced on October 23.

Since pleading guilty in 2004, Fastow has assisted prosecutors and victim lawsuits and has cared for his wife, Lea, and sons age 8 and 11, lawyers wrote in seeking leniency.

Experts said leniency is unlikely, given Fastow's admitted wrongdoing beyond his guilty plea, including personally profiting on the off the books deals at Enron's expense.

Fastow will face U.S. District Judge Ken Hoyt, who rejected leniency in sentencing another cooperating defendant, former Enron executive David Delainey, earlier this month.

Fastow, charged in 2001 in a 78 count indictment listing fraud and money laundering, pleaded guilty to two fraud counts in 2004 after his wife was charged with tax fraud.

Lea Fastow, a former Enron assistant treasurer, served one year in prison after pleading guilty to signing a false tax return.

Victims of the Enron fraud will be allowed to make statements prior to his sentencing. Anyone interested must sign in an hour before the Tuesday morning hearing.