Norway's Statoil on Tuesday said it would vastly expand its prospecting efforts in the Arctic, thought to hold one of the world's largest untouched deposits of oil and natural gas.

Statoil will drill nine wells in the Norwegian Barents Sea between December and the summer of 2013, the company said in a statement.

"This is a less challenging area, as the Norwegian Barents is one of the only Arctic areas with a year-round ice-free zone," said Statoil Exploration executive vice president Tim Dodson.

The campaign in the summer of 2013 will include the drilling of two or three wells in the Hoop frontier exploration area far north in the Barents sea.

"These will be the northernmost wells ever drilled in Norway," the company said.

Major energy companies have increased their efforts to explore the frigid Arctic waters after between 400 and 600 million barreles equivalent were discovered by Statoil in the Skrugard and Havis wells.

"After our Skrugard and Havis discoveries we still see attractive opportunities here," Dodson said.

But the new energy frontier has raised stiff resistance from environmentalists.

In recent days, Greenpeace activists have carried out brazen actions against the Arctic operations of Russian energy giant Gazprom.

Six Greenpeace International activists occupied Gazprom's rig in the southeastern section of the Barents Sea on Friday for 15 hours before being chased out, pelted by workers with chunks of metal and hosed with ice water.