WASHINGTON (MarketWatch) - The Federal Open Market Committee Tuesday lowered its target for overnight interest rates by three quarters of one percent to a record low 0.25%. At the same time, the central bank released a statement that signaled an aggressive posture. It said it would keep rates low "for some time" and continue to expand its balance sheet to stabilize the economy. The vote to lower the Fed funds rate was unanimous. The move was expected as economic data over the last two months has show a sharp drop in activity.