Mr. Crist's office said the investigation stems from a complaint from a " Florida citizen approximately two weeks ago," the office said in a statement.

The office said there are indications of steering business toward those carriers that pay the highest contingency fees, and bid-rigging, which would be a violation of the state's antitrust laws.

Penalties could range in fines of up to $1 million for corporate violations, $100,000 for individuals and for three times the amount lost due to illegal activities.

"At this point we are investigating the brokers and insurance companies for possible violations of anti-competitive activities," Mr. Crist said. "The subpoenas are part of a larger effort to ascertain whether insurance practices are being conducted lawfully, with no conflict, with insured citizens' best interest at the forefront."

Florida's chief financial officer, which governs insurance regulations in the state, established a task force to look into the issue. Mr. Crist said his office looks forward to working with the group.

The broker who received the subpoenas are: AON, Inc.; The Willis Group, Inc.; Brown & Brown, Inc.; Arthur J. Gallagher & Company; Acordia, Inc. doing business as Acordia Southeast, Inc.; Heath Lambert Group doing business as Heath Lambert Miami, LLC; Hilb Rogal & Hobbs of Vero Beach, Inc.; USI Holdings Corp. doing business as USI Insurance Services of Florida, Inc.; HUB Investment Corporation; and Marsh & McLennan Companies.

Companies that may receive subpoenas are: ACE Ltd.; American International Group, Inc.; CHUBB Corporation; Munich American Reassurance Company; The Hartford Financial Services Group, Inc.; and Zurich American Insurance Company.