The right's record showing heralded political instability in the affluent Alpine republic since the two main centrist parties will be hard put to re-establish a broad coalition even if they resolve the feuds that killed off their last alliance.
"Terrible," political analyst Anton Pelinka said of prospects for stable government in the near future.
"The strength of the far-right parties will make formation of a coalition incredibly difficult if you don't bring either into government," he told Reuters. Social Democrats have ruled out an alliance with the right over its anti-foreigner stances.
Initial projections put the Social Democrats at 30 percent and the Peoples Party at 25 percent, down from 35 and 34 percent respectively in 2006.
It was the worst result for both since World War Two.
Heinz-Christian Strache's far right Freedom Party was on target for 18 percent, compared with 11 percent two years ago, and Joerg Haider's right-wing populist Alliance for Austria's Future was on 11 percent, almost tripling its showing in 2006.
The two parties were once one, before an acrimonious split in 2005. A big question now is whether the two might cooperate to bolster the right's case for a share of power.
A throaty roar filled the air in Freedom's election tent in Vienna when the results flashed on a screen, with the crowd -- mainly young and middle-aged men drinking beer -- punching the air and shouting "bravo."
"The Social Democrats and Peoples Party have been punished and rejected. And the Social Democrats will have to make clear why they are not at least ready to go into talks about other coalitions," said Strache, a former dental technician.
By clinging to their status as Austria's largest single party, the center-left Social Democrats are expected to be asked by President Heinz Fischer to form the next government.
The environmentalist Greens were seen slipping to 10 percent from 11 percent, according to the early projections by Austrian state broadcaster ORF and national news agency APA.
Rightist Appeal Grows
Far-right Freedom and the somewhat more moderate Alliance benefited from the campaign's two most engaging leaders, protest sentiment against the dysfunctional outgoing coalition and popular anti-inflation proposals.
A broad coalition formed by the two mainstream parties collapsed in July after 18 months of deadlock.
"The biggest winner is collectively the radical right ... but that doesn't mean they can come together in a political partnership," said Richard Luther, an expert on Austria at Keele University in Britain.
"I think a grand coalition (of the two biggest parties) is still the most likely, (but) it would be relatively weak in terms of its legitimacy," said Luther.
Pelinka said the conservatives might go tactically into opposition and wait for the Social Democrats to fail in creating another coalition. "But where would they begin?" he said.
Faymann ruled out a coalition with Freedom, best known for its campaigns against immigrants and Islam, while a hook-up with the more palatable Greens would fall well short of a majority.
"This isn't a national catastrophe, it doesn't mean that Austria is a right-wing country. We knew this was coming," said Michel Palliardi, 33, who voted for the Social Democrats.
"A lot of this was in protest at the (outgoing) government. There is a sense of mistrust."
Freedom's first junior role in government so repelled the EU in 2000 that it briefly imposed sanctions on Austria. Strache wants to be interior minister and put a stop to immigration.
