S&P Downgrades Some Muni Bonds: The credit quality of state and local governments deteriorated in the first quarter, as Standard & Poor's Corp. lowered its ratings on $3.1 billion of municipal bonds while upgrading $1.4 billion of bonds. The rating company said it slashed ratings on 52 municipal bond issues, while giving improved ratings to 42 issues. Many of the lower ratings resulted from a decline in revenue, caused by the economic recession and other state budget problems. South Carolina and two major California issuers, Los Angeles Unified School District and San Francisco, had their ratings lowered. The three downgrades "primarily reflected financial pressure and fiscal deterioration," S&P said.