DALLAS (Standard&Poor's) Aug. 20, 2013--Standard&Poor's Ratings Services assigned its 'AAA' rating to Austin, Texas' series 2013 public improvement bonds, series 2013A public improvement refunding bonds, series 2013B taxable public improvement refunding bonds, series 2013 certificates of obligation, and series 2013 public property finance contractual obligations. At the same time, Standard&Poor's affirmed its 'AAA' long-term rating and underlying rating (SPUR) on the city's general obligation debt outstanding. We also affirmed our 'AA+' rating on the city's existing appropriation debt. The outlook on all ratings is stable. "Factors that support the 'AAA' ratings include our opinion of the city's strong and diverse economic base, strong financial management practices, and moderate overall debt levels coupled with rapid