NY -- Standard&Poor's CreditWire 8/27/96 -- Standard&Poor's today has affirmed its triple-`A' claims-paying ability rating of Swiss Reinsurance Co. (Swiss Re) following the company's announcement to buy the Mercantile&General Reinsurance Co. Ltd. (M&G Re; single-`A'-plus claims-paying ability rating) and its subsidiaries from Prudential Corp. for UK1,704 million. Standard&Poor's has affirmed its triple-`A' claims-paying ability rating of European Reinsurance Co. of Zurich, U.S.-based Swiss Reinsurance America Corp., and German-based Bayerische Ruckversicherung AG (Bavarian Reinsurance Co.), reflecting both implicit and explicit support from Swiss Re. The triple-`A' senior debt rating of SwissRe Finance (Bermuda) Ltd. and SwissRe Finance (U.S.) Inc. are affirmed, based on guarantees by Swiss Re. The amount of rated debt affected