A.M. Best Co. has affirmed the financial strength rating (FSR) of A++ (Superior) and issuer credit ratings (ICR) of “aa+” of the property/casualty subsidiaries of The Chubb Corporation (Chubb Corp) (NYSE: CB) also known as the Chubb Group of Insurance Companies (Chubb Group). Concurrently, A.M. Best has affirmed the ICR of “aa-”, all long-term debt and indicative ratings and the AMB-1+ on the commercial paper of Chubb Corp. In addition, A.M. Best has affirmed the FSR of A++ (Superior) and ICR of “aa+” of Chubb Atlantic Indemnity Ltd. (Chubb Atlantic) (Pembroke, Bermuda). The outlook for all ratings is stable, except for the commercial paper, which does not have an outlook. All companies are headquartered in Warren, NJ, except where specified. (See below for a detailed list of the companies and ratings.) The ratings reflect the Chubb Group’s superior risk-adjusted capitalization, excellent underwriting and overall operating performance and the sustainable competitive advantages within its specialty and upscale personal insurance businesses, which is demonstrated by its consistent outperformance of industry peers. The ratings also recognize Chubb Group’s comprehensive and proactive enterprise risk management, disciplined underwriting practices, strong franchise recognition and access to the capital markets through Chubb Corp. The group’s positive rating attributes are enhanced by its position as a leading insurer in the United States and its global presence in specialty markets. The strength of Chubb Group’s balance sheet is derived from its consistent generation of underwriting profits, despite the recent impact of catastrophes and competitive market conditions and a well-diversified book of business, which has led to excellent risk-adjusted capitalization. Chubb Group’s results also benefit from an above average total return on invested assets and strong underwriting and operating cash flows. These positive rating factors are partially offset by challenging market conditions and catastrophe and weather-related losses, which have impacted underwriting performance in each of the last three years. Catastrophe losses added approximately six, nine and 10 points to the group’s combined ratios for 2010, 2011 and 2012, respectively. Management remains focused on limiting exposures through actively monitoring these risks and maintaining a prudent reinsurance program. In addition, the group has historically recognized adverse development of the loss reserves associated with its asbestos and environmental liabilities, although overall development of loss reserves has been favorable in recent accident and calendar years. Given Chubb Group’s leading market position, specialty niche underwriting focus, prudent balance sheet liquidity, strong cash flows and excellent risk-adjusted capitalization, A.M. Best considers it favorably positioned and sufficiently capitalized to absorb these challenges and those posed by the continued competitive market.