Arch Capital Group Ltd. (ACGL) writes insurance and reinsurance on a worldwide basis. ACGL operates in two underwriting segments: insurance and reinsurance. Its insurance operations are conducted in Bermuda, the United States, Europe, Canada, Australia and South Africa. Its insurance operations in Bermuda are conducted through Arch Insurance (Bermuda), a division of Arch Re Bermuda. In the United States, its insurance group's principal insurance subsidiaries are Arch Insurance Company, Arch Excess & Surplus Insurance Company, Arch Specialty Insurance Company, and Arch Indemnity Insurance Company. Its reinsurance operations are conducted on a worldwide basis through its reinsurance subsidiaries, Arch Reinsurance Ltd., Arch Reinsurance Company, including treaty and property facultative reinsurance operations) and Reinsurance Europe Underwriting Limited. In April 2012, the Company acquired Ariel Re�s Credit & Surety reinsurance operations based in Zurich.