Aspen Insurance Holdings Limited is a holding company. The Company underwrites specialty insurance and reinsurance on a global basis. It manages its business as two business segments: Aspen Insurance and Aspen Reinsurance (Aspen Re). The reinsurance segment consists of property catastrophe reinsurance (including the business written through Aspen Capital Markets), other property reinsurance (risk excess, pro rata and facultative), casualty reinsurance (U.S. treaty, international treaty and global facultative) and specialty reinsurance (credit and surety, agriculture insurance and reinsurance, marine, aviation, terrorism, engineering and other specialty lines). The insurance segment consists of property and casualty insurance; marine, aviation and energy insurance, and financial and professional lines insurance. Aspen Re participates in alternative reinsurance market through Aspen Capital Markets, which is part of property catastrophe reinsurance line of business.