On the eve of a major speech in New York about corporate corruption, U.S. President George Bush promised Monday to propose stricter regulations of businesses and longer jail terms for executives who fudge financial statements.

"We have a responsibility to punish those who are guilty and protect those who have been hurt," Bush said in a news conference Monday. "That will restore confidence."

His comments come as the former chief executive of WorldCom refused to tell U.S. lawmakers how $3.85 billion in expenses at the beleaguered company was wrongly accounted for.

Canadian-born Bernard Ebbers and former chief financial officer Scott Sullivan exercised their rights to avoid self-incrimination under the U.S. constitution's Fifth Amendment during hearings Monday.

"Although I would like more than you know to answer the questions that you and your colleagues have about WorldCom, I have been instructed by my counsel not to testify based on my Fifth Amendment constitutional rights," said Ebbers. "But I do not believe I have anything to hide."

The U.S. House Financial Services Committee is trying to determine the facts behind the largest accounting scandal in U.S. history. It wants to know how the $3.85 billion was wrongly booked to hide losses of $1.22 billion over five quarters.

Ebbers was ousted from the telecommunications giant on April 30 because of WorldCom's huge debts and enormous personal loans.

"I'm proud of the work I did at WorldCom," said Ebbers. "It continues to be a valuable company."

Sullivan was fired from WorldCom on June 25, the same day the company admitted the bookkeeping error.

However, Ebber's successor, John Sidgmore and company chairman Bert Roberts targeted their criticism toward Arthur Anderson, the company's external auditor.

Roberts called the accounting mistakes "an outrage" and said he found it inconceivable that the Andersen team didn't uncover the improprieties.

In prepared testimony, Sidgmore said the problem was discovered internally.

"The kind of initiative demonstrated by our internal audit group is to be applauded and will continue to be encouraged."

Bush also pledged more money to help the U.S. Securities and Exchange Commission investigate corporate financial transgressions. The SEC has filed fraud charges against WorldCom, which is also being investigated by the U.S. Justice Department.

WorldCom's stock, which once traded for $63 a share in 1999, was world 25 cents last Friday.

Last week, Sidgmore apologized for the accounting scandal and asked for creditor and shareholder patience while he tries to turn the company around. WorldCom, whose interests include No.2 long-distance telephone company MCI, is battling to avoid bankruptcy.

WorldCom is the second-largest U.S. long-distance telephone company and carries half of the world's Internet traffic.

The U.S. House committee also took aim at Wall Street analyst Jack Grubman, who long-promoted WorldCom stock before downgrading his recommendation just before the accounting scandal erupted.

"I regret that I was wrong in rating WorldCom highly for too long,'' Grubman said in pre-prepard testimony. He insisted he had no advance knowledge of the company's impending accounting problems.