UNITED NATIONS — A former U.N. official pleaded guilty yesterday to soliciting hundreds of thousands of dollars in bribes from companies seeking U.N. contracts, the U.S. Attorney's office in New York said.

Secretary-General Kofi Annan waived diplomatic immunity for Alexander Yakovlev, a senior procurement officer, so that he could be prosecuted in U.S. courts. Yakovlev pleaded guilty to three counts of conspiracy, wire fraud and money laundering, which could bring 20 years each.

The 52-year-old Russian resigned in June after separate revelations that he helped his son get a job with a company doing business with the United Nations. Annan's office notified investigators of his further suspected corruption last month, said Annan's top aide, Mark Malloch Brown.

Annan said he would rescind immunity, if requested, for the former chief of the U.N. oil-for-food program, Benon Sevan, who has been accused of taking kickbacks from Iraqi oil sales. Sevan, who has denied wrongdoing, quit Sunday and returned to his native Cyprus, which does not have an extradition treaty with the United States.

Yesterday, the U.N. Independent Inquiry Committee, led by former Federal Reserve Chairman Paul Volcker, released a report alleging wrongdoing by the two officials.

The report said there was "persuasive evidence" Yakovlev received nearly $1 million in kickbacks from companies that had won about $79 million of U.N. contracts outside the oil-for-food program.

Investigators said Yakovlev had about $1.3 million in a West Indies bank account under the name of Moxyco Ltd., and they have traced about $950,000 so far to companies doing U.N. business.

Yakovlev also allegedly solicited payments from a French inspection company seeking an oil-for-food contract, offering secret bidding information to help it win the tender. Investigators found no evidence that the company, Societe General de Surveillance, paid a bribe, and noted it cooperated by passing on correspondence detailing the solicitation.

Yakovlev denied the charge, but a former FBI handwriting analyst said the notations on the letters were made by Yakovlev. One of the charges Yakovlev pleaded guilty to concerned the oil-for-food bribe solicitation.

In another aspect of his investigation, Volcker said his panel had discovered new e-mails suggesting Annan was aware Cotecna Inspection, the Swiss company that employed his son, was seeking a U.N. contract, despite the secretary-general's earlier denials to investigators.

Volcker said that the questions would be explored in another report expected in early September, but added there was no evidence Annan influenced the awarding of the contract to Cotecna.

In its report yesterday, its third such document to date, Volcker's committee alleged Sevan accepted payments from an Egyptian oil dealer to steer lucrative Iraqi oil contracts his way. The cash allegedly was routed through a trading company owned by Fakhry Abdelnour, a cousin of former Secretary-General Boutrous Boutrous-Ghali.

The report said African Middle East Petroleum transferred $580,000 to the account of Fred Nadler, Boutrous-Ghali's brother-in-law. Nadler then put $147,184 in New York bank accounts controlled by Sevan and his wife, the report stated.

Sevan has said the money was a gift from his now-deceased aunt, but Volcker called the claim "not credible." Volcker recommended Sevan's diplomatic immunity be lifted to allow a criminal investigation.

The Manhattan District Attorney's Office has said it is looking into the case but would not comment further.

In a resignation letter to Annan, Sevan declared his innocence and accused his old friend of scapegoating him for political reasons.

""I fully understand the pressure you are under, and that there are those who are trying to destroy your reputation as well as my own, but sacrificing me for political expediency will never appease our critics or help you or the organization," the letter said.