- Business
- Marsh & McLennan Companies, Inc. (NYSE: MMC; FSE: MSN.DE) is a global professional services firm providing advice and solutions in risk, strategy, and people. The company operates through four primary businesses: Marsh, the world's largest insurance broker offering risk management, insurance broking, and advisory services; Guy Carpenter, a leading reinsurance broker providing reinsurance treaty and facultative broking, analytics, and capital management solutions; Mercer, a provider of health, wealth, career, and human resources consulting including employee benefits, retirement solutions, compensation consulting, and HR transformation; and Oliver Wyman, a management consulting firm delivering strategic, economic, operational, and brand consulting services to businesses, governments, private equity firms, and public sector organizations. It serves corporations, public entities, insurance companies, associations, professional services organizations, private clients, and institutional investors across diverse industries worldwide, with operations in more than 130 countries.
Founded in 1871 and headquartered in New York, New York, the company generates revenue primarily from its Risk and Insurance Services segment (encompassing Marsh and Guy Carpenter), which accounts for approximately 65% of total revenue, alongside its Consulting segment (Mercer and Oliver Wyman).
In recent developments, Marsh McLennan announced in October 2025 plans to rebrand as Marsh effective January 2026, with its four main businesses adopting the Marsh brand progressively through 2027—including Guy Carpenter as Marsh Re and Oliver Wyman as a Marsh business—while creating a new Business and Client Services unit to drive innovation in data, AI, analytics, and operational excellence; its stock ticker will change to MRSH. The company continues its aggressive acquisition strategy, having invested $8.5 billion in 2024 and $224 million in the first nine months of 2025, including Marsh McLennan's Marsh unit acquiring three Hawaii-based brokerages (Atlas Insurance Agency, Pyramid Insurance Centre, and IC International) from Tradewind Group in late 2025 to expand in the Pacific market, another acquisition of Massachusetts-based Hayden Wood Insurance Agency in November 2025 for personal lines expertise, and Mercer's completions of SECOR Asset Management in May 2025 to bolster investment capabilities and Cardano in late 2024 to enhance pension services in the UK and Netherlands.