Two underwriters at Zurich Financial Services AG, the third-biggest American commercial insurer, pleaded guilty to charges they helped rig bids to help an insurance broker give business to favored clients.

The two men, John Keenan and Edward Coughlin, worked exclusively with Marsh & McLennan Cos., according to plea agreements at their arraignment yesterday in New York State Supreme Court.

The pleas bring to five the number of people who have admitted roles in the illegal business practices under investigation by New York Attorney General Eliot Spitzer.

“The investigation is proceeding carefully and methodically,” Mr. Spitzer said in a statement. “Our goal is to determine the full extent of wrongdoing in the industry and its effect on consumers.”

More than 17 people have been forced out or suspended since Mr. Spitzer sued Marsh, the world’s largest insurance broker, on October 14. Marsh’s chief executive, Jeffrey Greenberg, was forced to resign after Mr. Spitzer refused to negotiate with him.

Two executives from American International Group Inc. and one from Ace Ltd. pleaded guilty last month.

Messrs. Keenan and Coughlin each pleaded guilty to a misdemeanor under New York State’s Donnelly Act, which bars agreements that are in restraint of trade.

They face a maximum sentence of one year in state prison. The two employees no longer work at the company, said Zurich spokesman Keith Owens.

Messrs. Keenan and Coughlin were part of an unspecified number of employees in the excess-casualty unit suspended last week, Mr. Owens said.

In his complaint against Marsh, Mr. Spitzer said insurers inflated quotes as part of a phony bidding system Marsh designed to steer business to the insurers that paid it the highest fees.

Mr. Spitzer and other state officials told a U.S. Senate panel yesterday that alleged abuses they found in the insurance industry indicate the need for more federal oversight, including tougher antitrust rules.

Messrs. Keenan and Coughlin, who worked exclusively with Marsh Global Broking between 2002 and 2004, are expected to testify in future cases, Mr. Spitzer’s office said.

“I don’t think the attorney general’s office is going to bring any of these cases to trial,” said an attorney for Mr. Coughlin, Lewis Weiner. “They’re squeezing these low-level people and that’s not right.”

Supreme Court Judge James Yates set a trial date for Messrs. Keenan and Coughlin for January 27, 2005.

Mr. Spitzer filed his second complaint in the probe last week, suing Universal Life Resources Inc., a closely held broker based in San Diego.

That suit linked UnumProvident Corporation, MetLife Inc., and Prudential Financial Inc. to price-fixing and payoffs, bringing the total number of companies identified in the collusion to nine.

Zurich suspended several employees in America last week after it reviewed its business with insurance brokers, including Marsh, according to a Zurich spokesman, Daniel Hofmann.

The Zurich-based company won a contract two years ago to insure an $800 million school project in Greenville, S.C., according to the Marsh suit.

Marsh, which brokered the deal, gave the contract to Zurich because it expected the insurer to pay a lucrative fee, Mr. Spitzer’s complaint said. Zurich wasn’t named as a defendant in the suit.

Zurich’s review found “things that were reasonably concerning,” Mr. Hofmann said. “We had some concern when we looked into the activities and we decided it would be better to suspend these people right now.”

Zurich said it’s getting help in its investigation from the New York-based law firm LeBoeuf, Lamb, Greene & MacRae LLP. A LeBoeuf, spokesman Stephen, DiCarmine declined to comment on the probe.