UPDATE 1-Nippon Oil acquires new field stake in Vietnam

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TOKYO, Nov 16 (Reuters) - Nippon Oil Corp (5001.T) said on Friday its wholly owned subsidiary had acquired a 40 percent stake in the 16-2 field in offshore southern Vietnam. Nippon Oil, Japan's biggest oil refiner, said it had entered a production-sharing agreement with Vietnam state oil group Petrovietnam, which owns a 45 percent stake in the field through a subsidiary.

The acquisition of the block covering 2,785 square km (1,075 sq mile) marks the third field project in Vietnam for Nippon Oil.

The remaining 15 percent stake is owned by Joint Venture Vietsovpetro (VSP), a venture between Petrovietnam and Russia.

A Nippon Oil spokesman said it did not pay for the stake, but would invest around 3.5 billion yen ($31.78 million) in exploration and other costs.

The exploration work will last three years from this month, and two trial wells are to be drilled, Nippon Oil said. ($1=110.14 Yen) (Reporting by Osamu Tsukimori, Editing by Michael Watson)