The European Central Bank should leave interest rates unchanged as long as the outlook for inflation is in line with its price stability target, the OECD said. "It would seem reasonable for the ECB to hold its rate stable as long as the outlook for price developments remains in line with price stability over the medium term," the organisation said in a report on the euro zone economy. The ECB defines its price stability goal as a medium-term inflation rate below but close to 2 pct. Euro zone inflation is currently at 2.1 pct. The OECD said the ECB would need to act if the medium-term inflation outlook changed. It said a significant euro appreciation or a substantial weakening of activity might lead to consideration of a rate cut, but at the same time the ECB has to be vigilant about inflation risks from excess liquidity and knock-on effects from oil price rises.