W. R. Berkley Corporation, an insurance holding company, operates as a commercial line writer worldwide. The company operates through Insurance and Reinsurance & Monoline Excess segments. The Insurance segment underwrites commercial insurance business, including excess and surplus lines, admitted lines, and specialty personal lines. This segment also provides accident and health insurance and reinsurance products; insurance for commercial risks; casualty and specialty environmental products; insurance coverages for fine arts and jewelry exposures; excess liability and inland marine coverage for small to medium-sized insureds; and commercial general liability, umbrella, professional liability, directors and officers, commercial property, and surety products, as well as products for technolo…