OLDWICK, N.J.--(BUSINESS WIRE)--A.M. Best has assigned an issue rating of “bbb-” to the $125 million 7.5% subordinated notes to be issued by AmTrust Financial Services, Inc. (AFSI) (NASDAQ:AFSI), headquartered in New York, NY. The outlook assigned is stable. The offering may be increased upon exercise of an underwriters’ over-allotment option. Net proceeds from the sale of the notes will be used in part to finance the previously announced acquisitions of Warranty Solutions (including its subsid