OLDWICK, N.J.--(BUSINESS WIRE)--A.M. Best has affirmed the financial strength rating (FSR) of A (Excellent) and the issuer credit rating (ICR) of “a” of The Guarantee Company of North America (GCNA) (Toronto, Ontario, Canada). Concurrently, A.M. Best has affirmed the FSR of A (Excellent) and the ICR of “a” of GCNA’s subsidiary, The Guarantee Company of North America USA (GCNA USA) (Detroit, MI). The outlook for all ratings has been revised to negative from stable. The affirmations of GCNA’s rat