BOSTON (Standard&Poor's) Sept. 17, 2013--Standard&Poor's Ratings Services raised its rating on the City of Fitchburg, Mass.' general obligation bonds (GO) to 'A+' from 'A-' based on our recently released local GO criteria, USPF Criteria: Local Government GO Ratings Methodology And Assumptions. The outlook is stable. A pledge of the city's full faith credit secures these bonds. "The rating reflects our assessment of the Fitchburg's economy as adequate, with access to the broad and diverse economy of Worcester County," said Standard&Poor's credit analyst Apple Lo. Other factors include the city's: Strong budgetary flexibility, with available general fund reserves above 8% of expenditures for the past several years and no plans to significantly spend them down.