Moscow, May 16 (IANS/RIA Novosti): Russian state-run oil giant Rosneft has pledged to invest around $100 million in geological prospecting and drilling off Vietnam after it received approval for a new oil bloc there, Rosneft CEO Igor Sechin said.

"We have received approval for another bloc, 05-3/11, close to the existing bloc. We'll be able to use the existing infrastructure. This year, we'll spend about $27 million on geological prospecting while overall obligations (for Rosneft) for geological prospecting and drilling amount to about $100 million," Sechin said.

The Rosneft head signed a production-sharing agreement for the bloc Wednesday between TNK Vietnam, a subsidiary of TNK-BP taken over by Rosneft, and Vietnamese state company Petrovietnam.

Sechin said geological prospecting for the new bloc would take about two years but did not specify the amount the company might spend on the whole project.

Rosneft did not have any stakes in Vietnamese projects until it took over Russian-British joint oil venture TNK-BP, which had acquired from BP a 35 percent stake in the offshore gas condensate production Block 06.1, which contains the Lan Tay and Lan Do gas condensate fields.

Rosneft has offered Petrovietnam cooperation in eight blocks on the shelf of the Pechora Sea in the Russian Arctic, Sechin said.