Patrick G. Ryan, Aon chairman and chief executive, announced late Friday that "because trust and client satisfaction are top priorities for all of us at Aon, we are discontinuing a practice that has created enormous controversy and confusion. We cannot permit even the slightest impression of a conflict between acceptance of these commissions and our paramount obligations to our clients."

New York Attorney General Eliot Spitzer has charged in a civil suit that in the case of Marsh brokerage the incentive payments, known under a variety of fee labels, were payoffs by insurers in exchange for having business steered their way at inflated prices through rigged bids.

"We will work closely with insurance carriers, regulators and other constituencies to establish a new business model that ensures appropriate linkage of compensation to specific, measurable services in a way that is transparent, accepted and understood by our clients," Mr. Ryan said.

Aon, Mr. Ryan said, provides "important services on behalf of underwriters; however, certain current compensation models must change."

Aon said it has begun winding down contingent commission agreements and expects to complete the process by the end of 2004.

The Aon action came a day after London-headquartered Willis Group holdings said it was ending contingent fee commissions.

A spokesman for Mr. Spitzer's office would not comment on a report that a suit will shortly be directed at AON except to say that the investigation is continuing.

A call to an Aon representative for comment was not immediately returned.

In an Oct. 14 press release, shortly after the announcement that Marsh was being sued by Mr. Spitzer's office, Aon said that the practice of "soliciting ?fictitious quotes,' bid-rigging, and accepting payments from insurers not to shop quotes" would violate the firm's policies, and to its knowledge, no employees had engaged in such practices.

Aon added then that on the issue of accepting compensation, "it is a longstanding and well-known practice" within the industry, that is disclosed to clients.

On Friday, Moody's announced it has changed its debt rating for both Aon and Willis from stable to negative.

More details of Aon's plan will be provided in its earnings release this Thursday. A conference call is scheduled for Friday at 11 a.m. EDT.

The Webcast can be accessed at www.aon.com.