AM Best Co. has affirmed the financial strength rating of A (Excellent) and issuer credit ratings (ICR) of "a" of Allied World Assurance Company, Ltd. (Bermuda) (Allied World) and its operating affiliates. The outlook for all ratings is stable.

Allied World's ratings reflect its strong risk-adjusted capitalisation, stable management team and strong operating performance, Best said.

In 2008, Allied World was one of only a few Bermuda-based property/casualty insurers to grow shareholders' equity despite the market turmoil and catastrophe events. During 2008, Allied World established a US reinsurance company, expanded its presence in Europe and Hong Kong and acquired Darwin, which provided a book of US small account primary healthcare and professional liability business.

Partially offsetting these positive ratings factors is the current soft pricing environment in addition to the unstable financial markets. Best felt Allied was "well-positioned" for varying market conditions.