Marsh is the flagship operation of Marsh & McLennan Companies (MMC), one of the world's largest insurance brokerages. The company brokers insurance and provides risk management and consulting services to corporate clients, government agencies, and other organizations big and small. Marsh has some 25,000 agents and hundreds of brokerage locations in more than 100 countries. Marsh also provides risk financing, insurance program design, and underwriting management, as well as claims administration and technological support services. MMC affiliate Guy Carpenter provides similar brokerage and risk management services to reinsurance companies; other MMC companies include consulting firms Mercer and Oliver Wyman.