S&P Global Ratings has affirmed its A long-term counterparty credit rating on Chubb Ltd. with a stable outlook.

S&P said it revised its assessment of Chubb's financial flexibility to strong from adequate due to a criteria misapplication of its rating methodology for insurers.

"We had previously applied an analytical adjustment to score financial flexibility as adequate although the scoring of the financial flexibility subfactors indicated an assessment of strong," the rating agency said.

The strong financial flexibility assessment is based on the company's track record of capital raising and ability to raise additional funds, solid credit metrics and positive market indicators, S&P said.

The stable outlook is based on S&P's view that the company will restore capital to the extremely strong level by 2017 and successfully integrate legacy Chubb subsidiaries into its operations while maintaining underwriting discipline.

S&P also affirmed, with a stable outlook, the AA financial strength ratings of ACE American Insurance Co., Westchester Surplus Lines Insurance Co., Westchester Fire Insurance Co., Vigilant Insurance Co., Texas Pacific Indemnity Co. Pacific Indemnity Co. Pacific Employers Insurance Co., Insurance Co. of North America, Indemnity Insurance Co. of North America Illinois Union Insurance Co., Great Northern Insurance Co., Federal Insurance Co. Inc., Federal Insurance Co. Ltd., Federal Insurance Co. Executive Risk Specialty Insurance Co. Executive Risk Indemnity Inc., Corporate Officers & Directors Assurance Ltd., Chubb Tempest Reinsurance Ltd., Chubb National Insurance Co. Chubb Lloyds Insurance Co. of Texas Chubb Insurance Co. of New Jersey Chubb Insurance Co. of Europe SE, Chubb Insurance Co. of Canada, Chubb Indemnity Insurance Co. Chubb Custom Insurance Co. Chubb Bermuda International Insurance Ireland Designated Activity Co., Bankers Standard Insurance Co., Bankers Standard Fire & Marine Co., Atlantic Employers Insurance Co. ACE Tempest Life Reinsurance Ltd., ACE Property & Casualty Insurance Co. ACE Insurance Co. of the Midwest, ACE Insurance (Switzerland) Ltd., ACE Fire Underwriters Insurance Co. ACE European Group Ltd. and Chubb Bermuda Insurance Ltd.

In addition, the rating agency affirmed the AA- financial strength ratings of ACE INA Overseas Insurance Co. Ltd. Chubb Insurance Co. Ltd., Chubb Insurance Co. of Australia Ltd. and ACE Reinsurance (Switzerland) Ltd. with a stable outlook.

S&P Global Ratings and S&P Global Market Intelligence are owned by S&P Global Inc.