HOUSTON -- An Enron whistleblower testified on Wednesday that she later learned her job had been threatened after she raised financial concerns to company executives.

Accountant Sherron Watkins took the stand in the Houston fraud and conspiracy trial of Enron founder Kenneth Lay and former CEO Jeffrey Skilling.

Houston-based Enron filed for bankruptcy protection in 2001.

Watkins told how she met Lay after taking to heart his encouragement that Enron employees could bring any problems directly to him.

The meeting came in the wake of an anonymous memo she sent days earlier to Lay, then subsequently acknowledged her authorship, where she raised similar concerns.

Watkins read from the memo, in which she said, quote: "I am incredibly nervous we will implode in a wave of accounting scandals."

She left Enron in November 2002 and now is a consultant for corporate governance issues.

In earlier testimony on Wednesday, former Enron executive Vince Kaminski said Lay and Skilling knew about shady and shaky financial schemes put together to make Enron's finances look better, and did nothing about them.

Kaminski said that Skilling knew of concerns about the partnerships and complained that some risk-assessment staff acted more like "cops" than deal facilitators.

Kaminski said he told executives that "coming clean is our best fighting chance."

The next day, then-CEO Kenneth Lay reassured all employees Enron would survive. The company crashed two months later.

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.

Both men have pleaded not guilty.

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