Irish foes may have to consider unprecedented alliance as coalition thrown out

* Irish PM's party fares worse in second exit poll

* Only stable option may be alliance of civil war rivals

* Echoes recent deadlocked elections in Spain, Portugal

* Counting begins early Saturday, final results next week (Adds Fianna Fail leader quotes, first results)

By Padraic Halpin and William James

DUBLIN, Feb 27 (Reuters) - Ireland (Other OTC: IRLD - news) 's main opposing parties will have to start thinking about forming an unprecedented alliance, analysts said, after exit polls on Saturday suggested voters had rejected the ruling coalition, many opting instead for protest groups and independents.

Enda Kenny's government looks to be the latest victim of European voters' growing antipathy to mainstream politics.

Although under his premiership Ireland has bounced back from a bailout to become the continent's fastest-growing economy, voters said the fruits of the recovery had not been shared.

"There's total disillusionment with party politics. The independents and the smaller parties seem to be almost like the last hope for the country," said John McKeever, a voter in Dublin. "It (Other OTC: ITGL - news) 's not a recovery for a good 30-40 percent of the country. It's a rich man's recovery."

Exit polls suggested the only viable option may be a problematic alliance of old rivals Fianna Fail and Kenny's Fine Gael - although even their combined support was set to fall below 50 percent of the vote for the first time.

If neither side is able to form a government, however, fresh elections would have to be called.

The centre-right Fine Gael captured 25 to 26 percent of the vote, the exit polls said. That is far below the 36 percent it won five years ago and the 30 percent opinion poll rating it enjoyed at the start of campaigning.

Current coalition partner Labour was in line to win just 7 to 8 percent of the ballot, which spending minister Brendan Howlin said meant they were out of the equation for the next government.

Fianna Fail was set to rise to 23 percent.

One Fine Gael junior minister, Michael Ring, said he would "of course" be open to a prospective deal with Fianna Fail after another exit poll late on Friday showed a similar result. He was the first senior member of either party to say so after weeks of rejecting the notion.

WEEKS TO FORM GOVERNMENT

Fianna Fail leader Micheal Martin hinted that he would first try to form a government with other groups, however.

"We'll be putting a mandate before the Dail (parliament) on March 10 and seeking the support of others in the first instance and there'll be a large group of TDs elected outside of Fine Gael and Sinn Fein," Martin told national broadcaster RTE.

"We're committed to ensuring the country gets a good government, but it's going to take time."

But analysts said a coalition of Fine Gael and Fianna Fail - heirs to opposing sides in a civil war almost a century ago - was the only option.

"Either we could have another election now and do away with the count, or we'll let them muddle around for a month or so and maybe they can think the unthinkable," said Michael Marsh, a professor of politics at Trinity College Dublin.

While the parties have few policy differences, one minister described the prospect as a "nightmare" during the campaign.

Others fear it would allow left-wing Sinn Fein, the former political arm of the Irish Republican Army, which polled at 15-16 percent, to establish itself as the main opposition party.

Fianna Fail's general secretary told radio station Newstalk it was "not beyond the bounds of possibility" that final results could see it come out on top. Under Ireland's proportional representation system, exact results are difficult to call.

Fine Gael strategist Mark Mortell said that Kenny would "hold off making phone calls" until early next week but that there was a very high risk of a second election this year.

The first of 157 seats was declared at 1530 GMT with the final winners potentially not decided until early next week.

ANTI-ESTABLISHMENT VOTE

Framed as a debate over how to distribute the profits of accelerating economic growth, Kenny's campaign to "keep the recovery going" rang hollow with many voters yet to feel any impact after years of austerity.

The exit polls suggested a major transformation had occurred in the party system as a result, just weeks before the centenary of the 1916 Easter Rising, the most dramatic chapter of Ireland's struggle for independence from Britain.

Fine Gael and Fianna Fail, which have swapped power since the state's foundation, and Labour, the junior partner in many governments, were shunned in favour of independent candidates, smaller parties and the rising Sinn Fein.

At the start of the last parliament in 2011, the three parties held 80 percent of the seats.

"We're seeing a collapse of the two-and-half party system," said Paul Murphy, a member of one of the likely beneficiaries, the left-wing Anti Austerity Alliance and People Before Profit group.

The results echo recent elections in Portugal and Spain, where anger at austerity, perceptions of rising inequality and mistrust of established political elites left parliaments fragmented and parties struggling to form governments.

Uncertainty over the election outcome pushed the gap between Irish and French bond yields to its widest in eight months this week, although Ireland can still borrow near record lows. Robust growth of around 7 percent last year is seen as insulating its financial assets against a potential stalemate. (Additional reporting by Conor Humphries; Editing by Catherine Evans and Hugh Lawson)