A.M. Best Affirms Ratings of The Chubb Corporation.

OLDWICK, N.J. -- A.M. Best Co. has affirmed the financial strength rating (FSR) of A++ (Superior) and the issuer credit ratings (ICR) of "aa+" of the Chubb Group of Insurance Companies (Chubb Group) and its property/casualty members. Concurrently, A.M. Best has affirmed the ICR and senior debt ratings of "aa-" of Chubb Group's holding company, The Chubb Corporation (Chubb) (NYSE: CB), and the senior debt rating of "aa-" of Chubb Executive Risk Inc. A.M. Best also has affirmed the junior subordinated debt rating of "a", the AMB-1+ on the commercial paper and the indicative ratings on securities of Chubb. 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. All companies are domiciled in Warren, NJ, except where specified. (See link below for a detailed list of companies and ratings.)

The affirmation of the ratings for Chubb Group reflects its superior risk-adjusted capitalization, excellent underwriting and overall operating performance and favorable holding company liquidity. The ratings also are reflective of the group's well respected franchise, risk management expertise and disciplined underwriting culture and sustainable competitive advantages in its specialty insurance and upscale personal lines businesses.

The foundation of Chubb Group's excellent underwriting and overall operating performance rests with its persistent focus on strategic market segments and excellent business plan execution. Its superior capital position may also be ascribed to Chubb's strong management and leadership, broad financial flexibility and comprehensive, integrated and well documented enterprise risk management (ERM).

It should be noted that Chubb does not have exposure within its investment portfolio related to the sub-prime mortgage crisis. In addition, Chubb has maintained its longstanding and disciplined approach to capital and liquidity management while simultaneously repurchasing approximately $3.0 billion of its common shares over the past two years.

These positive rating factors are partially offset by Chubb Group's significant market share in the professional liability business, potentially exposing it to systemic events that may cause volatility in earnings. Additionally, the group is susceptible to natural and man-made catastrophes, although A.M. Best believes that these exposures are generally well controlled through the ERM process and financially manageable. While asbestos and environmental liabilities have become less of a concern over the past several years, the potential for continued claims emergence remains. Despite these factors, A.M. Best considers Chubb Group very favorably positioned and sufficiently well capitalized to absorb these challenges and those posed by increasingly competitive property/casualty markets. A.M. Best believes strong earnings generation in 2007, absent the unknown effect of fourth quarter catastrophes, should result in another year of solid surplus growth.

Chubb Atlantic's ratings recognize its secure capitalization, strategic importance and the implicit and explicit financial and operating support provided by Chubb. However, Chubb Atlantic has reported substantial adverse prior year loss reserve development in recent years -- largely on discontinued business -- which has resulted in significant underwriting losses and weak operating performance. A.M. Best expects Chubb Atlantic's operating performance to improve in 2007, in part due to lower reserve development.

Chubb's debt-to-total capital ratio at September 30, 2007 was 22.5%, up from 15.1% at year-end 2006. Taking into consideration Chubb's capital management in 2007, A.M. Best expects the company's financial leverage to approximate 20%-21% at year end. Despite the ongoing share repurchase program, liquid assets at the holding company are expected to be at a substantial level and more than sufficient to cover annual holding company expenses. A.M. Best views Chubb's conservative holding company cash management favorably, which has been considered in the company's ratings.

For a complete listing of The Chubb Corporation's FSRs ICRs and debt ratings, please visit www.ambest.com/press/103107chubb.pdf.

Founded in 1899, A.M. Best Company is a global full-service credit rating organization dedicated to serving the financial and health care service industries, including insurance companies, banks, hospitals and health care system providers. For more information, visit www.ambest.com.