Chicago - Detroit averted a rating downgrade yesterday by Standard & Poor's Corp. Instead, the rating agency opted to affirm a BBB rating with a negative outlook for the city's general obligation debt. Joe O'Keefe, a director at Standard & Poor's said that while a downgrade had been a possibility, problems with the city's finances were not significant enough to warrant the action. While the city is facing a $63.3 million budget deficit, positives such as strong management and budget controls "support the rating where it is," O'Keefe said. Detroit's plan to issue $125 million of deficit funding bonds this fall to eliminate the budget imbalance will not greatly increase the amount of deficit funding bonds the city has outstanding, said Steve Murphy, a director at Standard & Poor's.