NEW YORK (Standard&Poor's) May 20, 2013--Standard&Poor's Ratings Services said it raised to 'AA' from 'AA-' its rating on Seattle, Wash.'s municipal light and power system's parity lien debt. At the same time, we assigned a 'AA' rating to the series 2013 improvement and refunding revenue bonds of the system, which does business as Seattle City Light (SCL). The outlook is stable. "The upgrade is based on financial management strategies that have significantly increased reserves, and reduced the impact on the system's financial margins of wholesale electricity market volatility," said Standard&Poor's credit Peter Murphy. Other ratings strengths include: A low-cost hydro-based generation portfolio that can meet demand under most water conditions, including less-than-normal water conditions;
