An exit poll in Ireland's parliamentary election suggested the three biggest parties have won roughly equal shares and the country is headed for another coalition government.

The three main parties are all within 2% of each other in the exit poll, but Ireland's electoral system means it is likely Fianna Fail and Fine Gael will make up another coalition government.

Exit poll put left-wing nationalists Sinn Fein at 21.1 percent of votes, slightly ahead of two centre-right parties.