Four states, including Ireland, will open talks this week to negotiate a division of thousands of square kilometres of ocean floor surrounding Rockall in the north Atlantic which could hold billions of euro worth of oil and gas.
The talks are to open in the Icelandic capital Reykjavik on Wednesday. They will involve Ireland, the United Kingdom, Iceland and the Danish dependency, the Faroe Islands.
Under a new United Nations treaty, states will be allowed to claim a greater share of the ocean floor if they can show a direct link with their own land mass and if they apply before the 2009 closing date.
The British government, which is taking part in Wednesday's talks, is already preparing to lodge an application for control of the underwater landmass around Rockall to the UN Commission on the Limits of the Continental Shelf.
However, the British claim will not be acted upon by the UN body for now because it does not make decisions in cases where ownership of area is strongly disputed by neighbouring countries.
Last night the Department of Communications, Energy and Natural Resources said the unilateral British move was "not very helpful".
"The commission will not entertain a submission until the dispute is resolved, but there is some willingness to make a joint submission," said an official.
This week's talks, involving a Department of Foreign Affairs official, could lead to an agreement among the competing states that could finally put an end to a decades-old Anglo-Irish row about the disputed territory.
New deep-sea drilling technologies mean that previously inaccessible oil and gas deposits can now be made commercially viable.
The new international code will update the 1982 Law of the Sea Convention, which allows coastal states to own the seabed for 200 miles if it is part of a continental shelf.
The new limit is now to be extended to 500 miles offshore, although the rules will only apply to the seabed and not to the fish above it.
Ireland has already lodged a joint application, along with France, Spain and the United Kingdom, for a 60,000 sq km plot that straddles the Celtic Sea and the Bay of Biscay.
Under the UN Convention on the Law of the Sea, states may register their rights to a continental shelf if they can show that it extends from their territories before falling away into deep ocean.
