White Mountains Insurance Group, Ltd., through its subsidiaries, engages in the property and casualty insurance and reinsurance businesses. It operates in four segments: OneBeacon, Sirius Group, HG Global/BAM, and Other Operations. The OneBeacon segment offers insurance products related to professional liability, marine, energy, entertainment, sports and leisure, excess property, excess environmental, group accident, property and inland marine, public entities, technology, surety, tuition refund, and government risks. This segment provides a range of insurance products through independent agencies, regional and national brokers, wholesalers, and managing general agencies. The Sirius Group segment offers insurance and reinsurance products for property, accident and health, aviation and space, trade credit, marine, agriculture, contingency, and other exposures. This segment also specializes in the acquisition and management of run-off insurance and reinsurance companies. The HG Global/BAM segment provides insurance on municipal bonds issued to support essential the U.S. public purposes, such as schools, utilities, core governmental functions, and existing transportation facilities. The Other Operations segment offers investment management services to third parties; provides variable annuity reinsurance; and reinsures death and living benefit guarantees associated with variable annuities issued in Japan. The company offers its products and services primarily in the United States, Europe, Canada, the Caribbean, Bermuda, Latin America, and Asia. White Mountains Insurance Group, Ltd. was founded in 1980 and is headquartered in Hamilton, Bermuda.