--Samaras meets leaders of four other parties
--Conservatives say coalition deal should be reached within three days
--Analysts see parties reaching deal because of high stakes
--New government must pave way for return of troika of creditors
(Updates to rewrite first paragraph, add information on Democratic Left Party in eighth paragraph and add detail in final paragraph.)
By Stelios Bouras and Costas Paris
ATHENS--Greece's two leading pro-bailout parties appeared late Monday to be headed into an alliance that would give them the majority needed to keep promised reform policies on course, but they were scrambling to find support from others in Parliament for a broad cross-party coalition government.
After formally receiving an exploratory mandate from Greek President Karolos Papoulias earlier in the day, conservative New Democracy leader Antonis Samaras quickly met with the heads of four other parties late Monday. Following those meetings, Mr. Samaras signaled a deal between him and his Socialist party counterpart, Evangelos Venizelos, would be reached within three days.
"Mr. Venizelos and I are in agreement that, no matter what, a government of national salvation must be formed within the deadline for the mandate given to me by the president," Mr. Samaras said after the third of the four scheduled meetings.
Although New Democracy won the most votes in Sunday's elections, it doesn't control enough seats to govern on its own and must seek a coalition partner to form a majority in Greece's 300-member parliament. Its former coalition partner, the Socialist Pasok Party--which also supports the country's European-led bailout--came in third in the vote. Combined, the two parties would control 162 seats, giving them a comfortable margin of support.
The new government will face high 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.
Its first task will be to come up with 11.5 billion euros ($14.6 billion) or more of new austerity measures demanded by the country's creditors, which could further inflame the public.
Facing strident opposition in Parliament from Greece's anti-austerity Syriza Party--which came in a strong second in Sunday's vote--Mssrs. Samaras and Venizelos have been trying to rope in other party leaders to gain as broad as possible backing for the tough decisions that lie ahead.
One possible candidate could be the small, Democratic Left Party, which accepts the loan deal but wants Greece to ease the terms of the austerity measures.
But even without that support, the two are ready to reach a deal and have held advanced talks on forming a government, officials from both parties say. In separate remarks to journalists, Mr. Venizelos said issues relating to who would be the next prime minister and the allocation of cabinet portfolios was "an easy issue."
Already, two names have been floated as possible finance ministers in the new government: former European Commissioner Stavros Dimas and former Development Minister Kostis Hadjidakis--both New Democracy Party members.
But as of late Monday, there appeared to be little enthusiasm from at least three of the other parties in Parliament. Samaras first met with Alexis Tsipras, the leader of the leftist Syriza Party, which has become the new force in Greek politics after campaigning on a fierce anti-austerity ticket.
After the meeting, Mr. Tsipras urged Mr. Samaras to form a government that would seek to renegotiate the terms of a EUR130 billion loan agreement "as soon as possible," even though he made clear his party wouldn't be part of it.
"Greece's significant and reinforced ability to renegotiate the terms of its loan deal must not be wasted," Mr. Tsipras said. "We won't stand in the way, but we won't cede this right that was earned with our efforts."
Hopes that a coalition government is close at hand pushed Greek stocks more than 6% higher in early trading, led by gains in banking shares, before ending up 3.6% at the close.
Sunday's elections come some six weeks after an inconclusive May 6 vote that left Greece with a hung parliament. Despite 10 days of coalition talks then, Greece's political parties failed to reach a cross-party deal, forcing this month's second round. But this time around, analysts see New Democracy teaming up with Pasok, possibly even with the participation of the Democratic Left Party, because doubts over the country's future in the euro zone have grown sharply since the last elections.
"There is no comparison with today and a month ago; the stakes are much higher," said Anthony Livanios, a political analyst. "The Pasok and New Democracy agendas have a common denominator. Greeks know that they must go ahead with reforms or leave the euro zone."
Mr. Samaras has been an unequivocal backer of Greece's euro-zone membership, even though he reiterated Monday that he wants to tweak the austerity program Greece has promised its European and international creditors.
"We will abide by the agreement, but at the same time we're seeking an agreement on policies that will give the Greek people room to breathe," he said in remarks earlier Monday.
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.
Mr. Venizelos, who like Mr. Samaras also called for a national unity government, urged Papoulias to speed up party talks to ensure a new government is formed quickly. Both Mssrs. Venizelos and Samaras have asked the president to preside over a meeting of party chiefs--possibly Tuesday--to help find common ground.
--Nektaria Stamouli in Athens contributed to this article.