Politicians in Serbia are to try to hammer out a governing coalition following Sunday's inconclusive poll.
Prime Minister Vojislav Kostunica could end up playing kingmaker
The nationalist Serbian Radical Party claimed victory yet failed to gain an absolute majority. It is unclear if others are willing to share power.
The Radical Party's candidate for PM said that despite its gains it expects to remain in opposition.
Groups favouring EU membership won most seats. EU foreign ministers are now meeting to discuss ties with Serbia.
EU foreign policy chief, Javier Solana, said that despite the strengthened support for the anti-EU Radical Party, he hoped any new government would favour EU membership.
"The majority voted for forces that are democratic and pro-European," he said from Brussels.
Serbian Radical Party (SRS) - Tomislav Nikolic
Democratic Party (DS) - President Boris Tadic
Democratic Party of Serbia (DSS) - PM Vojislav Kostunica
Socialist Party of Serbia
Liberal Democratic Party
The EU has said it is ready to re-start preliminary membership talks with Serbia, blocked eight months ago, but only on condition that it co-operates in tracking down Balkan War criminals.
Initial results suggest that the Radicals (SRS) took 29% of the vote, the pro-EU Democratic Party (DS) 23% and Prime Minister Vojislav Kostunica's ruling centre-right Democratic Party of Serbia (DSS) 17%.
Poll monitors said 60.4% of registered voters had cast ballots.
The BBC's Nick Hawton in Belgrade says that Mr Kostunica, whose party came third, may be in a position to be kingmaker or negotiate a deal where he remains prime minister.
But weeks of negotiations may lie ahead, our correspondent says.
'Signal for Europe'
The SRS candidate for prime minister, Tomislav Nikolic, told Reuters news agency that he did not expect President Boris Tadic to give his party the mandate.
But he said it was unlikely that the other two parties - the DS and DSS - could form a functioning coalition and predicted fresh elections by the end of the year.
President Tadic has said that the pro-European groups should begin coalition talks.
Mr Tadic, who also leads the DS, said he hoped the outcome would produce a government capable of major reforms.
"I hope that the political message sent out from Serbia will increase Serbia's political credibility, and that will provide better conditions for our people," he said.
Mr Tadic told his supporters that his party would demand the prime ministerial post.
The BBC's Jonny Dymond in Belgrade says Mr Nikolic will probably end up sitting on the sidelines.
The party campaigned on the fight against corruption and keeping Kosovo within Serbia.
The party's official leader, Vojislav Seselj, is on trial for war crimes at the UN tribunal in The Hague.
The SRS ruled former Yugoslavia for part of the 1990s in coalition with the Socialist Party of Serbia (SPS) of the late leader Slobodan Milosevic.
Kosovo remains a key issue for the incoming government.
The mostly ethnic Albanian region is legally a province of Serbia but is under UN administration.
The UN's chief envoy for the province is expected next month to recommend some form of independence - something the SRS vehemently opposes.
The other main parties have proposed wide autonomy for Kosovo within Serbia.
This has been the country's first general election since its union with Montenegro was dissolved last year.