By Crispian Balmer and Gavin Jones

ROME (Reuters) - Italy's national election produced no outright winner on Sunday, according to exit polls that pointed to possible political gridlock, with voters backing anti-establishment and far-right parties in record numbers.

A rightist alliance emerged with the biggest bloc of votes, ahead of the anti-establishment 5-Star Movement, the largest single party, polls showed. The ruling center-left coalition came third, hurt by anger over poverty and mass immigration.

Full results are not expected for several hours, and Italian exit polls have previously given misleading initial readings.

Heavily indebted Italy is the third largest economy in the euro zone and prolonged political stalemate could make it the focal point of market concern now that the threat of instability in Germany has receded thanks to the revival on Sunday of a grand coalition under Chancellor Angela Merkel.

The euro edged marginally higher in Asia early on Monday, with investors awaiting clearer results from Italy.

A poll for RAI state television said a bloc of center-right and far-right parties would win 33-36 percent of the vote, short of the 40 percent analysts have said is the minimum needed to secure a majority under Italy's new electoral law.

Within the alliance, former prime minister Silvio Berlusconi's Forza Italia (Go Italy!) was seen winning 12.5-15.5 percent, the same as the League, which has allied itself to anti-immigration, anti-Islam parties across Europe.

The 5-Star, led by 31-year-old Luigi Di Maio, was forecast to take 29.0-32.5 percent, which would be a remarkable result for a group that was only formed in 2009. It has fed off public fury over entrenched corruption and economic hardship.

"We will be a pillar of the legislature," said a smiling Alfonso Bonafede, a close ally of Di Maio, told La7.

A center-left alliance dominated by former prime minister Matteo Renzi's ruling Democratic Party (PD) was projected to win 25-28 percent, but pollsters said the PD itself might end up only the fourth-largest group in the lower house of parliament.

"If this is the result, for us it is a defeat and we will move into the opposition," said PD lower house leader Ettore Rosato.

STALEMATE

During two months of grinding election campaigning, party leaders repeatedly ruled out any post-election tie-ups with rivals. However, Italy has a long history of finding a way out of apparently intractable political stalemate.

Parliament will meet for the first time on March 23 and formal talks on forming a government are not likely to start until early April.

Financial markets have appeared little concerned by the Italian ballot, but investors are likely to take fright at any suggestion the 5-Star could form a coalition with the League.

Exit polls suggested the two forces would have enough seats to govern together and they have in the past shared strong anti-euro views. While the League still says it wants to leave the single currency at the earliest feasible moment, the 5-Star says the time for quitting the euro has passed.

Founded by comedian Beppe Grillo, 5-Star has sought to allay fears in EU capitals over its policies, dropping some of its more radical proposals, like leaving NATO, and promising to be business-friendly if they win power.

It has always shunned the idea of entering any formal coalition. During the campaign, Di Maio said he would seek cross-party support for his program, which includes "drastic" cuts to corporate taxes, slashing red tape and guaranteeing a minimum monthly income of up to 780 euros ($963) for the poor.

This so-called "Universal Wage" has helped the party draw massive support in the underdeveloped south, with pollsters predicting the 5-Star could sweep most first-past-the-post seats in regions below Rome.

By contrast, Berlusconi and his far-right, populist allies were expected to win the majority of seats in the wealthier north, with the center-left squeezed into a narrow stretch of territory across central Italy, including Tuscany.

Populist parties have been on the rise across Europe since the 2008 financial crisis. Italy's mainstream parties have found it especially hard to contain voter anger, with the economy still 6 percent smaller than a decade ago and unemployment stuck at about 11 percent.

(Additional reporting by Isla Binnie and Steve Scherer in Rome; Editing by Mark Bendeich)