Jamie Olis, a former senior director of tax planning for the energy company, is obliged to serve nearly all of his sentence of 24 years and four months because there is no parole in the federal system. He is 38, and would be behind bars until he is 62.

"I take no pleasure in sentencing you to 292 months," U.S. District Judge Sim Lake said in ordering the prison term. "Sometimes good people commit bad acts, and that's what happened in this case."

The punishment "reflects Congress's intent that white-collar corporate fraud defendants receive harsh sentences," Lake observed from the bench.

The sentence easily surpassed those of some much more prominent fraud cases, and dwarfed those of some Enron Corp. executives who have pleaded guilty in that company's accounting scandal. Olis took the chance of a trial and was convicted.

Federal probation authorities maintained that Olis' actions in illegally disguising company debt in 2001 eventually resulted in more than $500 million in Dynegy stock losses, and they had asked for 24 to 30 years in prison.

The maximum possible sentence was 35 years for one count each of conspiracy, securities fraud, mail fraud and three counts of wire fraud.

Lake's courtroom was packed with Olis supporters wearing yellow ribbons. Among them were his wife, Monica, and the couple's 6-month-old daughter. Many, including Olis himself, quietly wept after Lake announced his decision.

"I want to thank all of our longtime supporters," Olis said after Lake gave him a chance to address the court. "It means a lot to us."

Olis' attorneys contended that the government can't possibly pinpoint stock losses caused by revelations of a 2001 deal that wrongly boosted cash flow because Dynegy, like other energy merchants, was besieged by months of bad news in the aftermath of Enron's collapse in December 2001.

David Gerger, Olis' appellate lawyer, said the defense recommended less than 10 years in prison.

"All you can do as a citizen is put your faith in the justice system, and that's what Jamie did," Gerger said when asked if his client should have pleaded out.

Olis will be expected to surrender to a federal prison within the next month, Gerger said. His attorneys want him to serve at a facility where Enron's former treasurer, Ben Glisan Jr., is serving a five-year stretch after pleading guilty to conspiracy.

Olis' sentence is more than double that which former Enron finance chief Andrew Fastow is likely to receive after pleading guilty to two counts of conspiracy in January and agreeing to help prosecutors build other cases. The judge is expected to recommend a 10-year term. Glisan pleaded guilty to conspiracy but refused to cooperate with prosecutors.

Last June, former Rite Aid Corp. chief executive officer Martin Grass pleaded guilty in a massive accounting fraud in a deal calling for an eight-year sentence. Former WorldCom chief financial officer Scott Sullivan pleaded guilty to charges of filing false financial statements that carry a maximum penalty of 25 years but is expected to get a reduced sentence in his plea deal.

Olis was charged in June alongside two co-conspirators, his former boss Gene Shannon Foster and a former company accountant, Helen Christine Sharkey. Foster and Sharkey each pleaded guilty to one count of conspiracy in August, and Foster testified against Olis in his November trial.

Foster said he, Olis and Sharkey were part of a larger group that crafted and approved an Enronesque natural gas deal dubbed "Project Alpha" in response to analyst concerns in 2000 that cash flow lagged behind recorded earnings from the trading unit.

Tax experts at Dynegy's then-auditor, Arthur Andersen LLP, had pitched an Alpha-like deal to create cash flow to fill the gap. Implemented in April 2001, Alpha improperly boosted cash flow by $300 million and cut taxes by $79 million. It came to light a year later under heightened accounting scrutiny after Enron's crash.

Alpha wasn't Dynegy's only problem. Shares began sliding when its ill-fated buyout of Enron crumbled in November 2001, days before Enron filed for bankruptcy. They fell below a dollar by October 2002 after Dynegy had ousted management, laid off workers and scrapped money-losing ventures.