HONG KONG--(BUSINESS WIRE)--A.M. Best has affirmed the financial strength ratings (FSR) of A+ (Superior) and the issuer credit ratings (ICR) of “aa” of Mitsui Sumitomo Insurance Company Limited (MSI) and Aioi Nissay Dowa Insurance Company Limited (ADI) (both domiciled in Japan). A.M. Best also has affirmed the FSR of A- (Excellent) and the ICR of “a-” of ADI’s subsidiary, Aioi Nissay Dowa Insurance (China) Company Limited (ADIC) (China). The outlook for MSI’s and ADI’s ratings is stable while t