The European Central Bank left interest rates unchanged on Thursday, holding them at record lows while it deploys a large scale money-printing plan aimed at lifting inflation out of negative territory.The decision to leave the cost of borrowing at record lows was widely expected after the ECB cut rates to rock-bottom levels last September and the bank's president, Mario Draghi, then said they had hit "the lower bound".At Thursday's meeting held in Cyprus, the ECB left its main refinancing rate, which determines the cost of credit in the economy, at 0.05 percent.It also kept the rate on bank overnight deposits at -0.20 percent, which means banks pay to park funds at the central bank, and held its marginal lending facility - the emergency overnight borrowing rate for banks - at 0.30 percent.Markets now turn their attention to Draghi's 1330 GMT news conference, with investors looking for more details on the ECB's programme of money printing to buy sovereign bonds - so-called quantitative easing (QE). The plan is due to begin this month.