By STELIOS BOURAS and COSTAS PARIS

ATHENS—Greece's conservative New Democracy party will begin talks with peers Monday on forming a pro-bailout coalition government after eking out a slim victory in Sunday's elections.
New Democracy party chief Antonis Samaras is scheduled to meet with President Karolos Papoulias Monday morning, where he is expected to be mandated with forming a cross-party administration.
With almost 100% of the vote counted, New Democracy was backed by 29.7% of voters, giving it 129 seats in the 300-seat Parliament. That includes a 50-seat bonus the party received for getting the most votes. The radical left Syriza party is second with 26.9% of the vote, or 71 seats.
New Democracy's likely coalition partner, the Socialist Pasok party, has garnered 12.3% of the vote, or 33 seats, allowing the two pro-bailout parties to form a majority government if they agree on a coalition. Another potential coalition partner is the Democratic Alliance party, which garnered 6.3% of the vote, amounting to 17 seats.
According to Greek law, Mr. Samaras has three days to strike up a cross-party deal, though New Democracy party officials believe that he might be able to do so in less time, depending on how talks progress on issues such as who will lead the coalition government.
"We hear some noise from Democratic Left that they would participate in a coalition if Samaras is not prime minister. That's out of the question," a New Democracy official said. "If necessary the coalition will be made up of Pasok and New Democracy."
Mr. Samaras has been an unequivocal backer of Greece's euro-zone membership, even though he has said he wants to tweak the austerity program Greece has promised its European and international creditors.
In the weeks leading up to Sunday's vote, Mr. Samaras sought to turn the elections into a de facto referendum on the euro, saying a vote for Syriza would be tantamount to voting for a return to the drachma, Greece's former currency.
On Sunday, he cast his party's narrow win as a foundation for rapprochement with Europe. "We will respect our signature and the country's obligations," Mr. Samaras said at a postelection news conference, surrounded by cheering supporters. He called on other parties to join him in a "national salvation" coalition government.
Pasok leader Evangelos Venizelos, who like Mr. Samaras also called for a national unity government, urged Mr. Papoulias to speed up party talks to ensure that a new government is formed quickly.
The new government will face huge hurdles, with a central administration threatened by a cash crunch within weeks, an economy in free fall and an angry public exhausted by two years of austerity measures.
The first task facing the new government will be to come up with €11.5 billion euros ($14.5 billion) or more of new austerity measures demanded by the country's creditors that could further inflame public opinion.
Late Sunday, euro-zone finance ministers said they expected Greece's troika of official lenders—the European Commission, the International Monetary Fund and the European Central Bank—to return to Athens as soon as a new government is in place.
A troika review must take place every three months for Greece to receive the next tranche of its €130 billion bailout package.
Write to Stelios Bouras at [email protected] and Costas Paris at [email protected]