New Delhi:  Indian national oil companies on Wednesday signed a series of agreements here with Russia’s state-run Rosneft to buy stake in Russia’s Vankor oil fields.

Under the agreements, ONGC’s overseas arm, ONGC Videsh Ltd. (OVL), will increase its stake in Rosneft’s Vankor project to 26 percent while Oil India, Indian Oil and Bharat Petro Resources, the exploration arm of Bharat Petroleum, will buy 23.9 percent between them in the same field.

Last year, India’s ONGC agreed to buy a 15 percent stake in Vankor in Siberia, which produced 22 million tonnes of oil in 2014.

By a separate share sale agreement, Oil India, Indian Oil and Bharat Petro Resources also agreed to purchase 29.9 percent stake in Rosneft’s Taas-Yuriakh field in eastern Siberia.

Though the value of the deals were not disclosed, Rosneft chief executive Igor Sechin told reporters here that the agreements represented the building of a “reliable energy bridge” between time-tested allies, India and Russia.

“These agreements with Rosneft will allow Indian companies access to productive resources in the Russian Federation, while permitting Rosneft to work in India,” Sechin told reporters on the sidelines of the signing event also attended by Petroleum Minister Dharmendra Pradhan and Russian Ambassador to India Alexander Kadakin.

Sechin also said Indian firm Essar Oil’s negotiations to sell 49 percent stake to Rosneft are at an advanced stage and will be finalised by the end of 2016.