Food giants McDonald's and Tesco have signed a "historic" agreement to not expand cod fishing into untouched parts of the Arctic, where the ice melt has sparked fears of a rush on unexploited areas, Greenpeace said Wednesday.

"This is a historic agreement that brings together the main players in the cod fishing" in the Barents Sea and the Norwegian Sea, said Frida Bengtsson, a marine environment specialist at Greenpeace.

"In the absence of significant legal protection of the icy waters of the northern Barents Sea, this is an unprecedented step from the seafood industry," she said.

The agreement, which has been signed by global seafood suppliers as well as British retail chains Tesco, Sainsbury's and Marks and Spencer, freezes bottom trawling in areas around the Svalbard archipelago.

It requires seabed mapping to determine the fragility of an area before it is opened up for fishing.

The agreement was brokered by environmental group Greenpeace and marks the first time the seafood industry has voluntarily imposed limitations on industrial fishing in the Arctic.

It means that any fishing companies expanding into pristine Arctic waters will not be able to sell their cod to major seafood brands and retailers.

The two dominant professional organisations in the region, Fiskebat for Norway and Karat for Russia, have signed up for the deal along with Danish company Espersen and British-based Young's Seafood.

"Fiskebat agrees not to send its trawlers to fish for cod in the Arctic areas in the Barents Sea, where no regular fishing has been practised in the past," said Jan Ivar Marak, an executive at the Norwegian company.

"Our customers tell us it's important they can be sure the fish on our shelves is caught in a way that doesn't harm the ocean environment, and this landmark agreement means vulnerable marine life in the Barents and Norwegian seas will be protected," said Giles Bolton, a sourcing director for Tesco.

No less than 189 trawlers have a licence to fish in the frigid waters of Svalbard, where 800,000 tonnes of cod are fished per year, according to Greenpeace.

"Cod is doing well, the stocks are good, but global warming is a real cause for concern," because it pushes trawlers further north, said Bengtsson.