A former Enron trader has pleaded guilty to conspiracy and has agreed to cooperate with prosecutors.
Mr Timothy Belden, the former head of trading in Enron's Portland office, has admitted to one count of conspiracy to commit wire fraud.
Mr Belden, 35, could get up to five years in prison at sentencing in April. He has been released on $500,000 bail.
He will also help federal prosecutors in their case against higher-ranking officials at Houston-based Enron.
Mr Belden's lawyer, Cristina Arguedas, said his client was following Enron's instructions when he handled his trades and will "make amends for that by cooperating with the government."
He is the first person to be charged in the manipulation of Western energy markets, and the third Enron figure to be prosecuted.
Mr Beldon was the mastermind behind the strategies described in memos that spelled out how Enron manipulated the California market, according to one lawyer investigating alleged manipulation of the market.
PA