A boy helps his father to cast his ballot at a polling station in Athens, Greece, 06 May 2012. Photo by BGNES
The EU and Germany have made it clear Greece must stick to the commitments it has entered into for the two EU/IMF bailouts, whatever the line-up of its next government.
Speaking to reporters on Monday, German government spokesman Steffen Seibert spelt out Berlin's position that "the agreed programs must be adhered to".
He added that Germany would support Athens in returning to competitiveness and financial stability, "whatever its government is".
Chancellor Angela Merkel said Greece's reforms were of "utmost importance".
Meanwhile European Commission spokeswoman Pia Ahrenkilde Hansen said Brussels "hopes and expects that the future government of Greece will respect the engagement that Greece has entered into".
She said the Commission was ready to help Athens with its "ongoing reform agenda".
The two main parties, New Democracy and Pasok, attracted less than a third of the vote as people backed anti-austerity parties, plunging Greece into political uncertainty and renewing questions about its future in the euro zone.
New Democracy leader Antonis Samaras will now face a struggle finding parties prepared to join a government.
With about 99% of votes counted, centre-right New Democracy (ND) is leading with 18.9%, down from 33.5% in 2009.