Dinh Huu Loc, director of the International Relations Department at PetroVietnam, said Zarubezneft's withdrawal was based on a decision by the Russian firm that the field had poor prospects.

In 1997 BHP Petroleum quit the disastrous project, giving its entire 43.75% stake to a branch of the Malaysian state oil company, Petronas, after the true field reserves fell far below even the most pessimistic forecast of 100 million barrels and BHP's share of production of less than 30 million barrels.

The failed investment cost BHP close to $300 million up front but the real pain for BHP was the loss of expected revenue from the field after it was touted to have potential for up to a billion barrels of recoverable oil in 1993.

Analysts at the time declared that the initial reservoir estimates, calculated by a joint Vietnamese and Russian group, were heavily overstated from the time of the initial discovery in 1988.

Zarubezneft's pull out is another massive set back for the field, located 200 kilometers south of Ba Ria Vung Tau province, which was set up as an independent investment of Vietsovpetro.