Euro zone finance ministers agreed in principle on Friday to extend heavily indebted Greece's financial rescue by four months, averting a potential cash crunch in March that could have forced the country out of the currency area. The deal, to be ratified once Greece's creditors are satisfied with a list of reforms it will submit next week, ended weeks of uncertainty since the election of a radical leftist-led government in Athens pledged to reverse austerity measures. 'Tonight was a first step in this process of rebuilding trust,' Jeroen Dijsselbloem, chairman of the 19-nation Eurogroup, told a news conference. 'We have established common ground again to reach agreement on this statement.' The agreement, clinched after the third ministerial meeting in two weeks of acrimonious public exchanges, offers a breathing space for the new Greek government to try to negotiate longer-term debt relief with its official creditors. But it also forced radical young Prime Minister Alexis Tsipras into a major political climbdown since he had vowed to scrap the bailout, end cooperation with the so-called 'troika' of international lenders and roll back austerity. 'It has been a laborious but eventually a constructive process,' International Monetary Fund managing director Christine Lagarde said.