NEW YORK (Bloomberg) - Aon Corp., the world's second-largest insurance broker, said it hired a law firm to investigate whether it complied with anti-bribery laws.

Aon is reviewing whether it broke the US Foreign Corrupt Practices Act and other laws in the US and elsewhere, the Chicago-based firm said in a regulatory filing yesterday. The probe started after inquiries from the US Securities and Exchange Commission and the Department of Justice, said David Prosperi, a company spokesman.

The queries "appear to relate not only to us but to others in the industry as well," Mr. Prosperi said. "We take issues like this very seriously. We intend to get to the bottom of it as quickly as we can." He said the review began in the third quarter.

Aon notified the UK Financial Services Authority and "certain other non-US regulators," as well as the SEC and the Justice Department, of the review, it said in the filing. Aon shares dropped 58 cents, or 1.3 percent, to $45.65 in New York Stock Exchange composite trading. They have climbed 29 percent this year.

Christine Walton, a spokeswoman for Marsh & McLennan Cos., the largest broker, declined to comment. Marisha Chinsky, a spokeswoman for No. 3 Willis Group Holdings Ltd., had no immediate comment. John Nester, an SEC spokesman, declined to comment. Jaclyn Lesch, of the Justice Department, did not immediately return a call.

Marsh & McLennan, based in New York, led Aon and London-based Willis in a ranking of 2006 insurance broking and consulting revenue by Business Insurance magazine.