The Central Bank of the Philippines has decided to slash its key rates by another 0.5 percentage points in a bid to maintain the differential between Philippine and foreign spreads and to prop up the economy. The move will bring down the central bank's overnight borrowing and lending rates to 11.5 percent and 13.75 percent, respectively, starting Feb. 5, bank governor Rafael Buenaventura said Feb. 1. He said the Monetary Board, the policy-making body of the bank, has ruled on another rates