The outlook rating for Webster-based The Commerce Group and its subsidiaries has been downgraded from stable to negative, according to rating company A.M. Best Co.

The firm said it also affirmed the financial strength rating (FSR) of A+ (superior) and issuer credit ratings (ICR) of "aa-" for Commerce Group, its lead company, The Commerce Insurance Co., and Commerce’s four inter-company pool members.

Commerce Insurance Co. is a major provider of both automobile and homeowners insurance in the Bay State.

The revised outlook reflects the weakening in the consolidated capitalization of Commerce’s parent organization, MAPFRE S.A. (Spain), A.M. Best said in statement.

The ratings reflect Commerce’s reduced, yet solid capitalization, strong operating performance and local market expertise.