NY -- Standard&Poor's CreditWire 1/22/98 -- Standard&Poor's today assigned its double-'A' rating to Plano, Texas' $50.05 million G.O. and refunding bonds series 1998. Additionally, Standard&Poor's affirmed its double-'A' rating on Plano's outstanding G.O. bonds. The outlook on the bonds was revised to positive from stable. The rating reflects: -- Solid assessed valuation trends, spurred primarily by strong demand for new homes; -- Conservative financial management resulting in healthy general fund reserves; -- Economic vibrancy due to the presence of corporate headquarters facilities and the city's proximity to the Dallas metroplex; and --Significantly above-average wealth and income levels. The high debt burden and considerable capital improvement plan are offsetting factors, however, concerns are mitigated by