WASHINGTON (BBC)-- Former Enron chief executive Jeffrey Skilling accused government prosecutors of trying to "rewrite history" during his fourth day on the witness stand.

He said they were misrepresenting Enron's business and making "absurd" allegations against him.

Along with Enron founder Kenneth Lay, he is charged with hiding billions of dollars of losses and of lying about the state of the energy-trading firm.

Both men deny the charges. Enron failed in 2001 with debts of $31.8bn (£18bn).

"I think they have purposely not looked at facts they should have looked at if they wanted to come to a more balanced and accurate conclusion," Skilling said to questions from his defense lawyer, Daniel Petrocelli.

He said the prosecution view wasn't "consistent with what really happened at the company".

They allege that Skilling and Lay used partnerships created by former finance chief Andrew Fastow to hide debts and losses and mislead investors about Enron's financial health.

Experts say Skilling's testimony could make or break his defense Fastow has admitted to earning millions of dollars from the partnerships he operated, but testified earlier in the trial that Skilling knew about the arrangements.

Fastow has already pleaded guilty to fraud charges and his testimony was part of a plea bargain agreement under which he has agreed to a 10-year prison sentence.

On Thursday Skilling maintained that he was devastated by Enron's demise, but reasserted that the company was healthy in the run-up to its collapse into bankruptcy.

"I'm devastated because a company that was a fine company was brought to its knees unnecessarily," he said. ------------------Long list of charges

His defense team is contending that he was misled by dishonest executives like Fastow, and that the company's collapse was caused by panic-selling from investors rather than serious accounting fraud.

Skilling is charged with 28 counts of conspiracy and fraud related to the company's collapse.

If found guilty he faces a maximum sentence of 275 years in prison - although any jail term is likely to be around 20 years - and tens of millions of dollars in fines.

Meanwhile Lay, 63, faces six charges of fraud and conspiracy and could face up to 45 years in jail if convicted.