Greek conservative New Democracy party came in the first place in the country's general elections with 20.99 percent of national votes, but failed to secure a clear parliamentary majority, preliminary official results showed on Sunday.

With 15.54 percent of the votes counted nationwide, according to the early projections issued by the Interior Ministry, the pro-bailout conservatives were followed by the anti-austerity Radical Left SYRIZA coalition which garnered 15.22 percent of votes.

The socialist PASOK party ranked third with a record low of 14.66 percent of votes as the tough two-year austerity drive to counter the debt crisis that has alarmed the international financial system took its toll.

The preliminary results are largely in line with those of exit polls released earlier which showed a dramatic shake-up of the traditional political map in the debt-laden country.

With the abstention rate estimated at about 40 percent, the results showed that seven parties will most probably enter the next 300-member strong parliament, while another three are close to clearing the three-percent hurdle to join in.

The nationalist Independent Greeks are projected to win 10.2 percent of votes, the Greek Communist Party 8.29, while the neo-Nazi Chryssi Avgi (Golden Dawn) party were set to make its debut in the parliament, securing 6.7 percent of votes. The Leftist Democratic Left follows with.5.9 percent of votes.

Official results are expected later on Sunday.

With the elections unable to produce a clear winner, the party with the most votes would have to seek a coalition with its rivals, according to the country's constitution.

Whoever comes on top will have three days to conduct coalition negotiations. If they fail, the mandate will go to the second party for a further three days, and then to the third party.

In case no coalition emerges, the president would call a new election.

Based on the preliminary results, the two main pro-austerity parties New Democracy and PASOK will struggle over the next days to renew their power-sharing partnership in the outgoing transitional administration led by technocrat Lucas Papademos.