Canada and France appear headed for an underwater showdown over the European country's attempt to gain exploration rights over a potentially energy-rich chunk of the Atlantic Ocean seabed.

The French government said Wednesday it will file a letter of intent with the UN laying claim to a larger swath of the seabed for its St-Pierre-Miquelon territory, just south of Newfoundland.

The roughly 6,000 inhabitants of the North Atlantic archipelago want to develop their economy by expanding their access to the seabed, which is potentially rich in gas, marine and oil resources.

But the move has drawn the ire of Canada, with Foreign Affairs Minister Lawrence Cannon swiftly announcing that France's decision to revisit the issue is regrettable.

The maritime boundary dispute between Canada and France was settled in June 1992 by the International Court of Arbitration in New York.

"Canada does not recognize France's claim to any area of the continental shelf in the northwest Atlantic Ocean beyond the area set out in the arbitration decision, and Canada has made France aware of its position on several occasions, and again recently," Cannon said in a statement.

"Canada will take all necessary measures to defend and protect its rights with respect to its continental shelf."

The island's elected member, Annick Girardin, was in Paris this week lobbying the French government and media to submit a letter to a UN commission claiming an extended continental shelf for St-Pierre-Miquelon.

Countries have until May 13 to state their claim with the commission.

Girardin said in an interview the letter is aimed at getting the two countries to reach an agreement on dividing up the resources and any economic windfall.

"It's really quid pro quo, it's really to sit down and know who can give what to the other and how we can live together in this region without the archipelago's economy being sacrificed," Girardin said.

Cannon said a final decision on the matter was made in June 1992.

But since then, according to Girardin, the economic fortunes of the islands, the last remnants of New France, have been in peril, and shrinking fish quotas and stocks have not helped.

"It's not like 6,500 people are going to ruin the Canadian economy, so make a little room for us," she said.

Noting Canada's unwillingness to negotiate the matter, Girardin said the case could end up back before an international arbitrator.

"But it's not my vision of things and in no way is it what the French government or the elected officials of St-Pierre-Miquelon want," Girardin said.

"We hope to negotiate with the Canadians."