W. R. Berkley Corporation (W. R. Berkley) is an insurance holding company. W. R. Berkley operates in the four segments of the property casualty insurance business: Specialty, Regional, Alternative Markets, Reinsurance and International. Specialty includes excess and surplus lines and admitted specialty lines. Regional include commercial lines property casualty. Alternative Markets include excess workers' compensation, monoline workers' compensation, accident and health, and insurance services. Reinsurance, on both a facultative and treaty basis and participating in business written through Lloyd's of London. International business includes selected regions throughout the world. In May 2011, it announced the formation of Berkley Re UK Limited. In June 2011, it announced the formation of Berkley Technology Underwriters, LLC. In April 2012, it formed Berkley Public Entity Managers, LLC.