Marsh & McLennan (MMC) has agreed to pay $850m to settle the New York attorney general Eliot Spitzer's accusations that it rigged bids and took kickbacks from insurers, it was announced today.

The settlement figure was larger than was originally expected by industry experts.

The money will be used to reimburse brokerage commissions to clients. The payback scheme will take four years to complete, Spitzer said in a statement.

MMC's broker arm Marsh is yet to confirm or deny Spitzer's allegations.