Greek power-sharing talks enter a third and final round Thursday, as parties in the crisis-hit country struggled to hammer out a coalition deal after general elections produced no outright winner.

The mandate to seek coalition partners passes to Socialist leader Evangelos Venizelos, whose traditionally dominant PASOK party was hammered in Sunday's poll, pushed into third place with just 13.2 percent of the vote.

Coalition talks have failed so far after the second-placed Radical Left Coalition party, or Syriza, insisted that Greece's tough austerity program - part of its international bailout commitments - be canceled or frozen.

Anger at the past two years of austerity and a deep financial crisis saw voters desert the formerly dominant two main parties and flock to smaller parties on the right and left. Syriza and its head Alexis Tsipras saw a strong boost, bringing the party into second place with 16.8 percent.

Election winner Antonis Samaras, whose New Democracy party garnered just 18.85 percent, passed the mandate on the first day after the election after not managing to reach any agreement.

Venizelos has three days in which to seek some form of agreement, although as all the party leaders have already met during the previous two rounds, that looks unlikely. If his efforts fail, the country's president will convene all the leaders in an last-ditch attempt to cobble together a coalition. If that is also unsuccessful, new elections will be called.

"The people have punished PASOK, because they considered it responsible for the crisis," Venizelos said.

In return for billions of euros in rescue loans from other European Union countries and the International Monetary Fund, Greece imposed harsh austerity measures that saw salaries and pensions slashed, tens of thousands of people lose their jobs and businesses close down.

Venizelos said the election result was a clear message that the Greek people rejected the dominance of any one party, and that he would continue pursuing efforts for a coalition.

"It is clear from the result that the people want a coalition government, handing no clear mandate to any single party," Venizelos told his party's deputies. "The Greek people want to remain in the euro."