NY -- Standard&Poor's CreditWire 7/18/97 -- Standard&Poor's today has assigned its double-'A'-minus rating to University of Pittsburgh (Pitt), Pa.'s $133 million university refunding bonds series 1997B. The rating reflects the university's: -- Role as a premier state-related institution; -- Competitive admissions and good student quality; -- Consistently good operating performance and substantial endowment; and -- Manageable debt burden. Proceeds will be used to refund a portion of outstanding series 1992A bonds, secured by Pitt's general obligation. Despite substantial public funding, Pitt has some private college characteristics. A majority of the board is nonpolitical appointments, and Pitt follows FASB standards for financial reporting. Management potential is good, guided by a new president and prominent board; key interim