Koenig, 50, pleaded guilty in August 2004 to aiding and abetting securities fraud, saying he knew Enron masked losses in a highly touted and unprofitable retail energy unit by folding it into the division that included the company's trading unit. Koenig, who has not yet told jurors of his admitted crimes, said in response to questioning by prosecutors Wednesday that he knew it was wrong to tinker with the earnings figures. Skilling faces 31 counts of fraud, conspiracy, insider trading and lying to auditors in the collapse of Enron, which left thousands jobless and cost investors billions of dollars.