International Marine Underwriters

International Marine Underwriters (IMU) offers a full range of ocean and inland marine insurance products.


A.W.G. Dewar's tuition refund plan protects schools and parents from the financial consequences of a student's withdrawal or dismissal from school.

Professional Lines

OneBeacon Healthcare Group

OneBeacon Design Professionals

OneBeacon Management Liability

OneBeacon Financial Services

OneBeacon Financial Services offers property and casualty coverages for commercial banks, savings banks and savings and loan institutions, security broker-dealers, investment advisors, insurance companies and credit unions.

OneBeacon Surety Group

OneBeacon Surety Group offers a broad range of commercial, custom and miscellaneous bonds targeting middle-market, Fortune 2500 companies written through a network of independent agencies, brokers and wholesalers. Business is serviced through eight regions throughout the United States.

OneBeacon Environmental

OneBeacon Environmental specializes in environmental risk solutions designed to address a variety of exposures for a broad range of businesses, including multiline casualty placements for the environmental industry.

OneBeacon Technology Insurance

OneBeacon Technology Insurance solely focuses on the technology industry, making it a source for technology insurance and risk management needs.

OneBeacon Accident Group

OneBeacon Accident Group focuses on analyzing and developing unique accident solutions for the transportation, non-subscription and corporate accident marketplace, while also developing specialized accident insurance programs.

OneBeacon Specialty Property

OneBeacon Specialty Property provides excess property and inland marine solutions that augment primary policies or self-insured retentions.

OneBeacon Program Group

OneBeacon Program Group provides a full range of multi-line package insurance solutions for select specialty programs overseen by dedicated MGAs, MGUs and Program Administrators.

OneBeacon Entertainment

OneBeacon Entertainment provides specialized commercial insurance products, including professional liability coverages, for the entertainment, sports and leisure industries.

OneBeacon Government Risks

OneBeacon Government Risks provides solutions for midsized municipalities and counties, special districts and other publicly funded agencies.

OneBeacon Crop Insurance

Multiperil crop insurance available through The Climate Corporation.

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