MOSCOW - Scientists say Russia could lay claim to a huge swath of potentially energy-rich territory under the Arctic Ocean after their discovery of a link between a major underwater ridge and Russia's coastal shelf, Russian media reported Friday.

The director of the Arctic and Antarctic Research Institute was quoted by the Izvestia daily newspaper as saying that an expedition has determined that the Lomonosov Ridge running across the North Pole is an extension of the Eurasian continent.

The six-week expedition on a Russian nuclear icebreaker measured 700 square kilometres of seabed and conducted a series of detailed scans and acoustic measurements of the geological relief, the newspaper reported.

"The Lomonosov Ridge forms an inalienable part of Russia's Siberian platform,'' institute deputy director Viktor Posyolov was quoted by ITAR-Tass as saying.

The scientists returned from their expedition earlier this week. Their data could provide support for Russia to lay claim to more than a million square kilometres of territory under the Arctic Ocean.

But the discovery could not be independently confirmed. No Russian officials could be reached for comment Friday, and Russia has not announced any formal claims based on the expedition.

"I'm not aware of any claim made by Russia,'' said Rejean Beaulieu, a Foreign Affairs spokesman in Ottawa.

The expedition did not come as a surprise, Beaulieu said. Canadian and Russian officials have discussed their respective continental shelf research programs, and the Russians have informed Canada about their plans for the expedition.

The Russia media reports said the scientists' find means Russia could lay claim to an area the size of Germany, France and Italy combined. The area may contain up to 10 billion cubic metres of hydrocarbons, along with diamonds and metal ores.

International law says that a country can claim exclusive economic rights within 200 miles, or 320 kilometres, of its shores. If a country can prove that its continental shelf extends beyond the 200-mile economic zone, it can argue that it should have similar rights over a bigger area.

But international recognition of such claim usually takes years. Beaulieu said a country has 10 years to make a submission to the United Nations for extending the delineation of its continental shelf beyond the 200-mile zone.

"Canada's sovereignty over the lands and the waters of the Arctic is well established based on history,'' Beaulieu said. "We will continue to assert our sovereignty in the Arctic, including our internal waters.''

Russia has repeatedly claimed wide swaths of undersea Arctic territory, though four other polar countries -- Canada, Denmark, Norway and the United States -- have objected to Moscow's bid, which was first presented to the United Nations in 2001.

The undersea Lomonosov Ridge runs some 1,800 kilometres across the Arctic ocean, stretching from islands off Siberia to Canada's Ellesmere Island.

Aside from the Russian claim that it's connected to the Eurasian continent, scientists in Canada and Denmark have argued that the ridge is an extension of their continental shelf.

Experts say global warming is opening up the Arctic to new economic pressures, as receding ice exposes new areas of ocean and tundra to exploration and ice-free zones result in shorter shipping lanes.