Negotiations will resume today over rights to the Rockall area of seabed in the north Atlantic.
The talks, which involve Iceland, Denmark, Ireland and the UK, will run over two days in the Danish capital, Copenhagen.
Diplomats hope eventually to reach a deal on territorial rights to the vast area, which covers about 422,000sq.km or about five times the size of Ireland.
Under a new UN treaty, states are allowed to claim a greater share of the ocean floor if they can show an undisputed direct link with their own land mass, but they must apply before a 2009 closing date.
Yesterday, Minister for Foreign Affairs Dermot Ahern expressed his hope that the talks would be fruitful but said 'further meetings may well be required before we can strike a deal'.
'Ultimately, it is in the interests of all four countries that we come to an agreement on the issue. It is in no one's interest to prevent agreement in the long term,' he said.
Rockall lies about 320km from the north-west of Ireland, the Outer Hebrides off the west coast of Scotland and the southern coast of Iceland.
Denmark claims rights to the island and seabed through its dependency, the Faroe Islands.
The Rockall meetings, which have been going on for five years, are part of wider moves by countries to lay claim to vast areas of the ocean in the search for new reserves of hydrocarbons and minerals.
Ireland has also lodged a joint application, along with France, Spain and the UK, for a 60,000sq.km plot straddling the Celtic Sea and the Bay of Biscay.
