Tranche Update on Marsh & McLennan Companies, Inc.'s Equity Buyback Plan announced on November 9, 2010.

Marsh & McLennan Companies is one of the world's leading suppliers of professional services to businesses. Net sales (including intragroup) break down by activity as follows: - risk management and insurance brokerage services (60.8%): risk management and insurance brokerage consulting services (84.5% of sales; Marsh; world's leader), and reinsurance services (15.5%; Guy Carpenter); - human resource management consulting services (39.2%; Mercer et Oliver Wyman Group): management of retirement programs and company benefits, risk management, organization, and change assistance consulting services, etc. Net sales (including intragroup) are distributed geographically as follows: the United States (47%), the United Kingdom (15.7%), Europe (16.2%), Asia-Pacific (13.2%) and other (7.9%).