Ace Ltd’s Bermuda operations have had their financial strength and counterparty credit ratings raised to AA- (very strong) by Standard & Poor’s.

The ratings agency announced on Friday that Ace’s core Bermuda, European and North American operating insurance companies would all benefit from the new rating, with a stable outlook.

“We raised the ratings on Ace and related subsidiaries to reflect our view that Ace has substantially met or exceeded all of our expectations since we revised the outlook to positive on December 19, 2008,” explained Standard & Poor’s credit analyst Laline Carvalho.

S&P said the key factors supporting the upgrade are the group’s very strong and consistent operating performance, very strong competitive position, positive management and corporate strategy, very strong and improved capital adequacy, very strong investments and liquidity, and improved financial flexibility. The group also benefits from strong enterprise risk management practices, which also support the ratings, the commentary added.

Ms Carvalho said Ace’s profits had been very strong in the past five years. “These results are better than those of many global insurance and reinsurance peers during the same period,” she noted. “In addition, Ace’s diversified platform has contributed to the group’s lower earnings volatility than many of its peers’ in recent years.”

Ratings are of huge importance to insurers as they indicate a company’s ability to pay claims.

In addition, S&P upgraded the issuer credit (senior debt) rating of Ace Ltd, the Ace Group’s Switzerland-based holding company, to “A,” citing the company’s “very strong liquidity and improved financial flexibility”.

“We’re pleased to earn this important recognition from S&P and believe these rating upgrades provide an added measure of security and confidence to our customers, business partners and investors,” said Evan Greenberg, Ace’s chairman and chief executive officer.

“Our financial strength and consistent operating performance are the direct result of a conservative approach to underwriting, investing, risk management and overall balance sheet management. We focus on the business we know - insurance - and are a stronger organisation financially as a result of that discipline.”

S&P also raised its financial strength and counterparty credit ratings for Ace’s Combined Insurance Company of America and Combined Life Insurance Company of New York subsidiaries two levels, also to “AA-,” noting that it now considers these entities core to Ace’s overall business.

Ace has made three acquisitions in recent months, expanding its presence in Asia, in particular.

S&P said it expected Ace’s consolidated premium writings to trend flat to modestly up in 2011, “reflecting management’s continued pruning in competitive lines of business and the expected incremental impact on premium volume of recently announced acquisitions”.

The ratings agency added: “We believe that Ace could grow more significantly, particularly in property/casualty lines, if its lines of business were to experience significant premium rate increases in coming years.”