Greek conservative leader Antonis Samaras, whose pro-austerity party came first in national elections but fell well short of a governing majority, is now trying to form a new coalition government. Samaras has three days in which to build an alliance, after receiving the formal mandate from President Karolos Papoulias Monday.

But initial exploratory talks with Alexis Tsipras, the 38-year-old head of the second-placed Radical Left Coalition party, failed, increasing fears that Samaras — or anyone else — will be unable to forge a new government that will command a majority in Parliament.

"The campaign positions of Mr. Samaras are at the opposite end of the alternative proposals of a left-wing government," said Tsipras, who strongly opposes Greece's bailout commitments.

"There can be no government of national salvation, as (Samaras) has named it, because his signatures and commitments to the loan agreement do not constitute salvation but a tragedy for the people and the country." Another election, possibly as soon as next month, looms for a country that is reliant on international support to avoid bankruptcy.

Sunday's vote saw parties backing the draconian international rescue package lose their majority in parliament — raising the chances of a possible Greek exit from the common euro currency.

The uncertainty weighed on markets across Europe, with the Athens exchange closing 6.7 percent down.

Official results showed conservative New Democracy came first with 18.85 percent and 108 of Parliament's 300 seats. Samaras, who backs Greece's bailout commitments for austerity but has called for some changes to the bailout plan, will launch coalition-forming talks later in the day.

"I understand the rage of the people, but our party will not leave Greece ungoverned," Samaras said.

But even with the support of the only other clearly pro-bailout party elected, Socialist PASOK, New Democracy would fall two seats short of a governing majority.

If the deadlock does not ease, Greece faces new elections under a caretaker government in mid-June, about the time it has to detail new drastic austerity measures worth €14.5 billion ($19 billion) for 2013-14.

In June, Athens is also due to receive a €30 billion ($39.4 billion) installment of its rescue loans from the other countries in the 17-strong eurozone and the International Monetary Fund. If aid is cut off, analysts at Commerzbank estimated, the country would have trouble paying its debts by autumn.