OLDWICK, N.J.--(BUSINESS WIRE)--A.M. Best has downgraded the financial strength rating (FSR) to A (Excellent) from A+ (Superior) and the issuer credit ratings (ICR) to "a+" from "aa-" of the pooled members of Western World Insurance Group (Western World) (Keene, NH). Western World is owned by Validus Holdings Ltd. (Validus) (Hamilton, Bermuda) [NYSE:VR]. Validus completed its acquisition of Western World on Oct. 2, 2014. Validus' flagship company is Validus Reinsurance Ltd., which maintains an