NEW YORK—The Risk & Insurance Management Society Inc. said it is “disappointed” by Aon Corp.’s decision to again accept contingent commissions.

Aon announced Wednesday its decision to resume accepting various forms of compensation, including supplemental and contingent commissions. Aon and its largest rivals—Marsh & McLennan Cos. Inc. and Willis Group Holdings P.L.C. —had been barred from accepting the profit- and volume-linked commissions under a five-year ban that was lifted earlier this year.

In a statement regarding Aon’s move, RIMS said it “maintains its opposition to the practice of collecting contingent commissions and is disappointed in Aon’s decision.”

“RIMS urges Aon to join other large brokers in agreeing not to accept contingent commissions,” Scott Clark, RIMS secretary and director of RIMS External Affairs Committee and risk and benefits officer for Miami-Dade County Public Schools, said in the statement. “Ultimately, we would like to see the insurance industry as a whole adopt practices that place the broker in a position that best serves purchasers of insurance.”

Willis previously said would not resume collecting contingents on its core retail brokerage business worldwide, citing an inherent conflict of interest in the compensation practice. Marsh said it would not accept contingent commissions within its core brokerage operations for large account and middle-market business in the United States and Canada. However, Marsh said it will accept contingents within its Marsh & McLennan Agency L.L.C. subsidiary and within its U.S. and Canadian consumer business.

RIMS’ statement reiterated its position that contingent commissions should be universally banned, and called Aon’s move “a step backwards with regard to the level of service it provides to its clients.”

The statement said RIMS will continue to call upon all brokers to refrain from accepting contingent commissions, which it said “pose an inherent conflict of interest and interfere with the relationship of trust between the broker and insurance consumer, regardless of the nature of the client or the intermediary.”