The nation’s largest insurance brokerage on Monday agreed to pay $850 million in restitution to end an investigation into bid rigging, price fixing and the use of hidden incentive fees, according to New York Attorney General Eliot Spitzer.

Marsh & McLennan Companies, which is based in New York, will provide $850 million over four years to policyholders hurt by the conflicts of interest and will change its practices, Spitzer said. The company also will issue a public apology calling its conduct “unlawful” and “shameful,” Spitzer said. And the company will publicly promise to adopt reforms, he added.