Established in 1967, W. R. Berkley Corporation is a premier commercial lines property casualty insurance provider. Each of the operating units in the Berkley group participates in a niche market requiring specialized knowledge about a territory or product. Its five business segments include specialty insurance, alternative markets, reinsurance, regional property casualty insurance and international operations. The specialty units underwrites complex and sophisticated risks, including workers compensation and property coverage and general, professional, product, excess and umbrella liabilities, as well as aviation, commercial transportation and program business insurance. The regional units write commercial lines coverage for small- and mid-sized business firms and governmental entities. This segment also writes surety coverage. The alternative markets units offer insurance products and develop and administer self-insurance programs and other alternative risk transfer mechanisms. The reinsurance units write reinsurance on both a facultative and treaty basis. The companys international business operates in selected regions. Headquartered in Greenwich, Conn., W. R. Berkley Corporation owns Admiral Insurance Company, Carolina Casualty Insurance Company, Monitor Liability Managers and Nautilus Insurance Company.