PURCHASE, N.Y.--(BUSINESS WIRE)--National Public Finance Guarantee Corporation (National), an indirect subsidiary of MBIA Inc. (NYSE: MBI), today announced that Standard & Poor’s Ratings Services (S&P) has affirmed its AA- financial strength rating of National with a Stable Outlook. In its June 29 report affirming National’s rating, which is available on National’s website, S&P recognized National’s extremely strong capital adequacy position, strong liquidity and operating performan