Ace Ltd. has played a key role in helping those impacted by the Gulf of Mexico oil spill to receive compensation.

But now the Switzerland-based company, which has substantial operations in Bermuda, is phasing out of the business of handling claims tied to the disaster.

Ace assumed oversight of claims at the request of BP in April after the Deepwater Horizon oil rig exploded and sank, chief executive officer Evan Greenberg said in a conference call with investors last week.

"After processing more than 100,000 claims, we are now working with BP on transitioning claims-handling to Ken Feinberg," Mr. Greenberg added.

Mr. Feinberg is the administrator of the $20 billion fund set up by BP to pay victims.

Also during the call, Mr. Greenberg spoke out against contingent commissions, the once-banned payments that insurers pay to entice brokers

Mr. Greenberg said they create a conflict of interest and ought not to become prevalent again. Aon Corp., the biggest insurance broker, said last month it is considering bringing back the once-hidden payments that insurers pay to supplement the fees it takes from the buyers of coverage. Marsh & McLennan Cos., ranked second by brokerage revenue, said in March it will take contingent commissions at its unit serving mid-size US clients.

"If customers tolerate the practice of contingents, their use over time will likely become more prevalent," Mr. Greenberg said. "Frankly, I hope that does not occur."

Regulators in New York, Connecticut and Illinois in February released the two insurance brokers and Willis Group Holdings Plc, the No. 3 broker, from a ban on accepting contingent commissions. The ban resulted from a 2005 probe by former New York Attorney General Eliot Spitzer.

Brokers are supposed to find the best insurance policies for clients, so the insurance companies' payments to the brokers to direct business to them were a conflict of interest, Spitzer alleged at the time. He negotiated a ban on the practice to settle investigations of fraud and anticompetitive practices.

Following the states' February lifting of the ban, brokers now must reveal the contingent fees if clients ask.

"Unlike agents who represent insurance companies, brokers represent their clients," the purchasers of the insurance coverage, Mr. Greenberg said. "In fact, if I had it my way, clients and not insurers would compensate brokers. But that's just not a reality."

Aon, based in Chicago, and New York-based Marsh & McLennan appealed to officials for redress in 2008 as regulators opened a review. London-based Willis said it won't take contingents and called Aon's stance last week "troublesome and ambiguous".