* Scientists to gather data for territorial claim
* Denmark claim would overlap with Russia's, Canada's
By John Acher
COPENHAGEN, July 27 (Reuters) - Denmark will dispatch a scientific expedition to the Arctic Ocean at the end of the month to gather data before it submits a formal claim to a vast tract north of Greenland that includes the North Pole.
Such a claim would be made under the United Nations Convention on the Law of the Sea (UNCLOS), setting up a possible clash of interests with fellow Arctic coastal states Russia and Canada that are making their own claims.
"We need the data that we plan to acquire on this cruise," said Christian Marcussen, the expedition's chief scientist from the Geological Survey of Denmark and Greenland. "But ... we are quite confident that we will be able to make a submission."
Denmark admits it is interested in staking a claim to a part of the planet believed to be rich in untapped oil and gas, but rules out a unilateral "land grab" or being drawn into confrontation over competing claims.
"I reject the confrontation scenarios that have been presented in the media and academic circles," Klaus Holm, Denmark's Arctic ambassador, said.
"If there is any area where every party has an interest in cooperating, it is the Arctic. The challenge is so huge and the areas are so vast."
The expedition will sail from Svalbard off northern Norway on July 31 aboard the Swedish icebreaker "Oden" and will gather seismic and depth data to substantiate a future possible claim, for which the deadline for Denmark is November 2014.
Denmark has identified five potential claim areas off the Faroe Islands and Greenland - both parts of the Kingdom of Denmark.
Copenhagen has already submitted claims for areas north and south of the Faroes and for two areas south of Greenland to the Commission on the Limits of the Continental Shelf (CLCS) which assesses the scientific validity of such claims.
Any dispute would, however, need to be resolved through negotiations between states, and not by the CLCS.
The other area Denmark has identified - likely to be the most sensitive part of any future claim - is roughly 150,000 square kilometres (58,000 sq miles) extending north from Greenland and including the North Pole.
For that claim to be credible, much depends on whether the expedition is able to gather data to prove that the Lomonosov Ridge, an underwater formation spanning 1,800 kilometres (1,118 miles) across the pole, is an extension of Greenland's land mass.
Russian scientists claim that the ridge is an extension of Russia's land mass, but that does not exclude that it could also be an extension of Greenland and Canada, Marcussen said.
Under the U.N. convention, a country can extend its 200- nautical-mile economic zone if it can prove that the continental shelf is a natural extension of its land mass.
Russia caused controversy in 2007 when a mini-submarine took the Russian flag to the seabed at the North Pole, sparking accusations of imperialism.
Marcussen said he didn't rule out stopping at the pole to plant a Danish flag on the ice, as his team did in 2009, if it happened to be on the icebreaker's route.
But he said that was not the goal of the 45-day expedition and that any flag would be removed after such a ceremony. (Editing by Andrew Osborn)