Statoil, Norway's national oil company, signed a deal with Venezuela on Wednesday to step up operations in the oil-rich Orinoco Belt.

Two US oil majors walked away last year from multibillion-dollar projects in the region over disagreements with the government.

Statoil is to quantify the reserves of the Junin 10 block in the Orinoco Belt, possibly the largest deposit of extra-heavy crude oil in the world, with the possibility of then developing them.

"We see enormous reserves potential in Venezuela," Thore Kristiansen, who runs Statoil's operations in Venezuela, told the Financial Times.

President Hugo Chávez says he wants the reserves certification process underway in the Orinoco Belt to be complete by 2010. He hopes this will boost reserves from 100bn barrels to more than 300bn, more than any other country.

Statoil has a 9.7 per cent stake in a nearby block, Petrocedeño (formerly Sincor), which Mr Kristiansen said is producing roughly 200,000 barrels per day. "If Junin 10 proves to have reserves of the magnitude of Petrocedeño, there is huge potential," he said.

Exxon (NYSE: XOM - News) Mobil and ConocoPhilips walked away from projects in the Orinoco Belt last year. They refused to agree to new terms after state-owned PDVSA, announced it would increase its stake in their projects, choosing instead to file for international arbitration.

Statoil, Chevron, Total (NYSE: TOT - News) and BP accepted the terms.

Industry analysts say Venezuela is in desperate need of foreign investment and expertise. PDVSA has been struggling since a damaging strike five years ago resulted in the loss of many of its most experienced and qualified employees. Meanwhile its financial resources are stretched as Mr Chávez is diverting a large portion of oil income towards social programmes.

Following the government's decision to take a controlling stake in all oil projects, many analysts are expecting a similar move this year in the gas sector.