WASHINGTON (AP) - The Securities and Exchange Commission asked a federal judge on Monday to force Kenneth L. Lay, the former head of Enron Corp., to turn over documents the agency is seeking in its investigation of the business practices that led to one of the largest corporate bankruptcy filings in U.S. history.

The SEC said it had filed the request with the U.S. District Court in Washington, arguing that Lay was wrong to contend that turning over the documents would violate his constitutional rights against self-incrimination.

"The documents being withheld by Lay appear to be corporate records, which Lay may not withhold from production based on any personal rights he may have under the Fifth Amendment," the SEC said in a statement announcing its action.

Lay's spokeswoman and his attorney did not immediately return calls seeking comment.

Enron spiraled into bankruptcy in late 2001, part of a wave of corporate accounting scandals that engulfed not only the Houston-based energy trading company but such other big corporate names as WorldCom, Global Crossing and Adelphia Communications.

The highest-ranking Enron executive charged to date is former chief financial officer Andrew Fastow, who faces nearly 100 criminal charges including fraud, money laundering, conspiracy and obstruction of justice. Fastow has pleaded innocent and is free on $5 million bond as he awaits trial next April.

Earlier this month, Ben Glisan Jr., Enron's former treasurer, pleaded guilty to conspiracy and was sentenced to five years in prison.

Federal prosecutors said Glisan made no deal to implicate higher-ups such as Lay, but that his sentence -- the maximum under the law -- could send what one federal lawyer called "a somewhat chilling message."

Glisan worked for Fastow, who has been accused of masterminding the schemes that led Enron into bankruptcy in 2001 amid devastating disclosures of inflated profits, hidden debt and questionable accounting.

While the government has not filed criminal charges against Lay, the former chairman, or Jeffrey Skilling, the company's former chief executive, the two were named in a civil lawsuit filed in June against Enron and several former executives and directors.

The civil suit filed by the Labor Department seeks to recover hundreds of millions of dollars in retirement money that Enron employees lost when the company went into bankruptcy.