Greece's conservative opposition New Democracy party has elected a reformist as its new leader.

Former administrative reform minister Kyriakos Mitsotakis has defeated party stalwart Evangelos Meimarakis in a leadership contest open to all party members. About 400,000 people were eligible to vote Sunday.

With only partial results available, the 62-year-old Meimarakis, a former minister, parliamentary speaker and New Democracy interim leader from July to November 2015, called 47-year-old Mitsotakis to concede defeat and congratulate him.

New Democracy officials announced that Mitsotakis is leading Meimarakis, 51 percent to 49 percent, with 70 percent of polling precincts reporting. The final results will be announced Monday.

In the first round, held on Dec. 20, Meimarakis had led Mitsotakis, 39.8 percent to 28.5 percent. Two other candidates were eliminated.