Duperreault’s career spans 40 years. He was president and chief executive officer of Marsh & McLennan Companies from 2008 to 2012. Before joining Marsh, he served for four years as non-executive chairman of ACE Limited, a global insurance and reinsurance company, CEO of ACE Limited from October 1994 through May 2004, and as the company’s president from October 1994 through November 1999.
Prior to joining ACE, Duperreault served in various senior executive positions with AIG and its affiliates from 1973 to 1994.
Duperreault is chairman of Attune, a data-enabled company established by Hamilton Insurance Group, AIG and Two Sigma. He is the chairman emeritus of Blue Marble Microinsurance and former chairman of the board of overseers of the School of Risk Management of St. John’s University, New York.
Duperreault is a member of the boards of the International Insurance Society, IESE Business School, Insurance Information Institute, Bermuda Institute of Ocean Sciences (BIOS), Johnson Controls, and Saint Joseph’s University, Philadelphia, Pennsylvania.
He is credited by the Insurance Hall of Fame with helping to transform Bermuda from an island nation with a small, reinsurance-focused market into a global insurance centre.  He currently resides in Bermuda.
In March 2013, Duperreault was asked by Bermuda’s Finance Minister, the Hon. E.T. Richards, to chair the Spending and Government Efficiency (SAGE) Commission. The Commission’s primary objective was to make government more efficient, cost-effective, transparent and user-friendly. The SAGE Commission submitted a final report with recommendations on October 31, 2013.