An insurance broker accused by New York Attorney General Eliot Spitzer of bid-rigging and price-fixing faces another threat: lawsuits filed by angry customers and the company’s own shareholders upset that the company’s stock has plummeted.

Civil lawsuits against Marsh & McLennan Companies Inc., some of which seek class-action status, take numerous forms. At least seven federal lawsuits had been filed as of yesterday, and a California attorney has filed a lawsuit in state court.

Potential litigants number in the tens of thousands, one lawyer said.

“I think everybody is filing these cases in response to Eliot Spitzer’s action,” said a partner at Wolf, Haldenstein, Adler, Freeman and Herz in New York, Mark Rifkin. Mr. Rifkin filed a lawsuit on October 15 in federal court in New York, a day after Mr. Spitzer filed a lawsuit against Marsh & McLennan.

The lawsuits repeat many of Mr. Spitzer’s criticisms of the contingent commissions or placement-service agreements. Mr. Spitzer accused Marsh & McLennan of taking incentive fees as payoffs from insurance companies to steer corporate clients their way, rather than get those customers the best prices for corporate property and casualty policies.

The fees are in addition to ordinary commissions that brokers receive from insurance companies.

Lawsuits seeking class-action status demand reimbursement to investors for stock purchased in Marsh & McLennan, claiming that the alleged actions of Marsh & McLellan devalued the stock. The cost of insurance also was artificially raised, ultimately costing consumers higher premiums, the lawsuits say.

The market loss for Marsh & McLennan after Mr. Spitzer’s lawsuit was filed October 14 was “billions and billions of dollars,” Mr. Rifkin said.

Shares in Marsh & McLennan fell 25% the day Mr. Spitzer sued. Moody’s Investors Service put Marsh & McLennan’s debt rates on “outlook negative,” which often precedes a downgrade. Several brokerages, including Prudential Equities Group, lowered their ratings on the stock.

The allegations forced the resignation of Marsh & McLennan’s chairman and chief executive, Jeffrey W. Greenberg. The company also announced it was suspending the use of “market services agreements” with insurance carriers, which Mr. Spitzer has alleged were used to rig bids that cheated customers.

A spokesman for Marsh & McLennan declined to discuss the civil lawsuits yesterday, saying the firm does not discuss litigation.

A lawyer at the California firm of Lerach, Coughlin, Stoia, Geller, Rudman, and Robbins, Ted Pintar, said his firm sued Marsh & McLennan and Aon, another brokerage firm, in state court.

Lawyers are seeking a halt to the payment of commission fees, monetary damages, and are demanding that the brokerage firms give up profits made from the fees, he said.

The law firm also has sued the brokerage companies in U.S. District Court in New York.

A spokesman for Aon did not immediately return a call seeking comment.

United Policyholders, a San Francisco-based insurance consumer group, has sued Marsh & McLennan in state court in San Diego, accusing the firm of unfair business practices in violation of state law. The lawsuit seeks an injunction and a fact-finding on how to distribute damages.

“People are not getting the best product at the best price,” she said.