The European Central Bank said it will launch a three-day quick tender today to add liquidity after concerns over U.S. subprime mortgage losses continued to roil credit markets and drove overnight interest rates higher. ``This liquidity-providing fine-tuning operation follows up on the operation conducted yesterday and aims to assure orderly conditions in the euro money market,'' the Frankfurt-based ECB said in a statement. The minimum bid rate for the tender will be 4 percent, the ECB added. Time for the submission of bids for the liquidity providing operation is 10:50 a.m. Frankfurt time. Today's announcement comes after the ECB yesterday pumped 94.8 billion euros ($130.2 billion) in cash into markets. The overnight euro rate rose to 4.27 percent today, compared with the ECB's benchmark refinancing rate of 4 percent. This morning the ECB said it will continue to ``closely monitor'' the conditions on the euro money market in response to a sudden demand for cash. Central Banks = Plunge Protection Teams