W.R. Berkley Corp. is an insurance holding company, which engages in the property casualty insurance business. It operates through the following segments: Insurance and Reinsurance & Monoline Excess. The Insurance segment includes excess and surplus lines, admitted lines, and specialty personal lines throughout the United States, as well as insurance business in the United Kingdom, Continental Europe, South America, Canada, Mexico, Scandinavia, Asia and Australia. The Reinsurance and Monoline Excess segment involves in the reinsurance business on a facultative and treaty basis, primarily in the United States, United Kingdom, Continental Europe, Australia, the Asia-Pacific region, and South Africa. The company was founded by William R. Berkley in 1967 and is headquartered in Greenwich, CT.