Venezuela has signed a series of multibillion-dollar agreements with foreign and domestic companies to develop oil fields in the country's Orinoco region.

The agreements signed on Wednesday is the largest oil investment decision taken during Hugo Chavez's 11 years old presidency.

The deals also come three years after Chavez nationalised operations in Orinoco.

Rafael Ramirez, the country's oil minister, said Petroleos de Venezuela (PDSVA) will create joint ventures with two consortiums of mostly foreign companies to develop two blocks in the Carabobo area of the Orinoco belt, one of the world's largest
known oil deposits.

US-based Chevron and Spain's Repsol led groups that will tap into the OPEC member's 100-plus billion barrels of reserves.

Seeking foreign partners

Falling prices in oil is said to be the impetus behind Venezuela and other producer nations seeking partnerships that they avoided during the recent commodities boom.

"This international investment is absolutely necessary for us, we could not develop the Orinoco Belt alone," Chavez told oil company officials during a ceremony in the Miraflores presidential palace.

"This is mutually beneficial. You are here because you need to be here. These are relationships of equals, of friendship."

The Carabobo oil tender includes three projects slated to produce 1.2 million barrels per day following years of slumping oil production in Venezuela.

Repsol will take 11 per cent in its project, the same stake as consortium partners Petronas of Malaysia and ONGC of India.

The state-run PDVSA will take 60 per cent, with two other Indian companies taking the remainder, a Repsol official said.

Chevron will lead a second project along with consortium partners that include Japan's Jogmec, Mitsubishi, and Inpex, plus Venezuela's Suelopetrol.

The government did not receive offers for a third project.