OREANDA-NEWS. A.M. Best has upgraded the financial strength rating (FSR) to A+ (Superior) from A (Excellent) and the issuer credit ratings (ICR) to “aa-“ from “a+” of Transatlantic Reinsurance Company and its subsidiaries (collectively referred to as TransRe). In addition, A.M. Best has upgraded the ICRs to “a-” from “bbb+” and the issue ratings of Alleghany Corporation (Alleghany) [NYSE: Y] and Transatlantic Holdings Inc. The outlook of each rating has been revised to stable from positive. TransRe and Alleghany are headquartered in New York, NY.