Three former Marsh brokers in the US have been acquitted of bid rigging-related charges that followed a 2005 investigation by then New York Attorney-General Eliot Spitzer.

Former head of excess casualty Joseph Peiser and two subordinates, Greg Doherty and Kathleen Drake, were among eight people accused of colluding with insurance companies to rig the market for excess casualty insurance between November 1998 and September 2004.

Last year, former Marsh executives William Gilman and Edward J McNenney were found guilty on an anti-trust charge but were acquitted of all other charges, including fraud and grand larceny. They have lodged an appeal.

Without admitting wrongdoing, Marsh’s parent company paid $US850 million ($945.5 million) in a 2005 civil settlement of the matter.