DALLAS (Standard&Poor's) April 4, 2013--Standard&Poor's Ratings Services assigned its 'AA' long-term rating to the Nashville&Davidson County Metropolitan Government (Metro), Tenn.'s approximately $405 million series 2013A general obligation (GO) improvement bonds. At the same time, Standard&Poor's affirmed its 'AA' long-term and underlying rating (SPUR) on Metro's existing GO debt. The outlook on all ratings is stable. The rating reflects our view of Metro's deep and diversified economic base and its role as an economic center, as evidenced by its strong per capita retail sales," said Standard&Poor's credit analyst Sarah Smaardyk. "Further supporting the rating is our view of the Metro's moderate overall debt levels," Ms. Smaardyk added. Officials plan to use