Greece's pro-bailout parties have won a slim majority, easing fears the country might be on course for an exit from the euro. The result has been greeted with relief by the markets, and German chancellor Angela Merkel.
The leader of Greece's center right New Democracy hailed the result as a validation of the country's commitment to the euro after his party won the largest share of the vote.
"The Greek people voted today to stay on the European course and remain in the euro zone," New Democracy leader Antonis Samaras told jubilant supporters. "There will be no more adventures. Greece's place in Europe will not be put in doubt."
With the votes almost fully counted, New Democracy had won 29.6 percent of the vote, while the leftist anti-bailout Syriza party came close with 26.9 percent. Winning the largest share makes all the difference under the Greek electoral system, with the top party being awarded a bonus of 50 parliamentary seats.
Syriza leader Alexis Tsipras conceded the election to Samaras late on Sunday. He had earlier said the bailout deal would be "history" on Monday if he won.
There had been speculation that a Syriza win would lead to a default of Greek debt, possibly forcing an exit from the eurozone.
Congratulations by telephone
Chancellor Angela Merkel's office said she had congratulated Samaras by phone late on Sunday.
New Democracy was set to take129 seats in the 300-seat assembly. Meanwhile the socialist PASOK party, which gained 13.3 percent of the vote, secured 33 seats.
After results were announced, the euro rose against the US dollar and yen, and world stock markets looked set to make gains.
Speaking as the early news of the vote came through, German Finance Minister Wolfgang Schäuble said that, if confirmed, Germany "would consider such a result a decision by Greek voters to forge ahead with the implementation of far-reaching economic and fiscal reforms in the country."
Samaras has said he wants to renegotiate the loan terms, calling for an extra two years to make cuts demanded by the EU and International Monetary Fund (IMF ).
Room for maneuver
German Foreign Minister Guido Westerwelle hinted that there may be some room for flexibility on the time frame for Athens to meet its commitments.
"There can't be substantial changes in the engagements" said Westerwelle, referring to the commitments made by Greece in the bailout deal. "But I can imagine we discuss again a delay."
A similar note of compromise was sounded by the International Monetary Fund indicating it was prepared to renegotiate Greece's borrowing program.
"We take note of the election results in Greece and stand ready to engage with the new government on the way forward to help Greece achieve its objective of restoring financial stability, economic growth and jobs," a statement read.
Sunday's election was the second in six weeks after May 6 polls failed to produce a government.
The country has sought bailouts twice since May 2010, amounting to about 347 billion euros ($442 billion).
rc/mr (AFP, AP, dpa, Reuters)