HOUSTON -- A former Enron executive testified Wednesday that the company fudged its earnings figures with the knowledge of executives Jeffrey Skilling and Kenneth Lay.

Mark Koenig is Enron's former chief contact for investors. He was the first witness to testify at Skilling and Lay's fraud trial in Houston.

Koenig told jurors the two men were closely involved in company operations and sought to boost Enron's stock price, which required impressing stock analysts.

Koenig described two instances in which quarterly earnings were raised because Enron wanted to beat Wall Street estimates.

Jurors also heard part of several Enron conference calls from 2000 and 2001 in which Koenig said Skilling exaggerated the success of Enron's broadband division.

Koenig pleaded guilty to aiding and abetting securities fraud, and agreed to cooperate with the government.

Koenig is one of 16 Enron executives who have pleaded guilty.

The defense has suggested many were pressured into striking deals when they're not guilty -- and will tell government officials anything they want to hear.

Enron was once the nation's seventh-largest company.

Before 2001, it was considered an innovative new-economy maverick and admired as a top stock performer. But a spectacular collapse left thousands jobless and slammed Wall Street with billions in losses.

Skilling faces 31 counts of fraud, conspiracy, insider trading and lying to auditors for allegedly lying about Enron's financial strength.

Lay faces seven counts of fraud and conspiracy for perpetuating the alleged scheme after Skilling resigned in August 2001.

The trial is expected to last four months.

Both men have pleaded not guilty.

If convicted, each could face decades in prison and millions of dollars in penalties.