New York ? Former WorldCom CEO Bernard Ebbers was charged Tuesday with falsifying the books at the long-distance company in the biggest corporate fraud case in American history, and his chief financial officer pleaded guilty and agreed to testify against him.

Ebbers was accused in a federal indictment of taking part in a scheme to falsely inflate earnings by $11 billion. He was charged with securities fraud, conspiracy and making false filings with the Securities and Exchange Commission.

Former Chief Financial Officer Scott Sullivan agreed to plead guilty to the same charges and cooperate with prosecutors in hopes of reducing a potential 25-year prison sentence.

“I took these actions, knowing they were wrong, in a misguided effort to preserve the company to allow it to withstand what I believed were temporary financial difficulties,” Sullivan, 42, of Boca Raton, Fla., said in court.

In a steady voice, Sullivan said he was motivated to plead guilty by “sincere remorse and a deep sense of contrition.”

Ebbers, 62, of Jackson, Miss., was to be arraigned today.

Ebbers resigned from WorldCom in April 2002, well after its stock price had begun a steady decline and soon after questions began to swirl about the company’s finances.

Two months later, WorldCom announced it had uncovered nearly $4 billion in hidden expenses — the beginning of a spiral that would uncover a fraud now estimated at $11 billion, the biggest in U.S. history.

Atty. Gen. John Ashcroft announced the indictment in New York, saying, “America’s economic strength depends on the integrity of the marketplace.”

“No one,” Ashcroft said, “stands above the law.”

Ebbers’ attorney, Reid H. Weingarten, said no “fair-minded jury” would conclude that his client acted with criminal intent.