New Delhi, Sept. 15: ONGC Videsh Ltd (OVL) - the overseas arm of state-owned Oil and Natural Gas Corporation - has signed an agreement to buy an additional 11 per cent stake in Russia's largest oilfield by production in Siberia for about $930 million.

The deal will raise OVL's stake to 26 per cent in the field.

The agreement, announced on March 16, is expected to receive approvals from the boards of the companies as well as the Indian and Russian governments by the end of 2016.

The company and its wholly owned subsidiary ONGC Videsh Vankorneft Pte Ltd, Singapore, "jointly signed definitive agreements with Rosneft, the national oil company of Russia for acquiring additional 11 per cent stake in JSC Vankorneft, a company organised under the law of Russian Federation, which is the owner of Vankor field and North Vankor licence," the company said in a statement.

The agreement was signed by OVL chief executive and managing director Narendra K. Verma and Rosneft chairman Igor Sechin in Moscow. Vankor accounts for 4 per cent of Russian oil production.

The daily production from the field is around 4,21,000 barrels per day (bpd) of crude oil on an average. Following the latest acquisition, OVL's share of daily oil production from Vankor will be about 1,10,000 bpd.

"The acquisition of additional 11 per cent bears significant strategic importance and will add about 30 per cent to OVL's existing production at the current rate and approximately 2.2 million tonnes of oil and 1.0 billion cubic metres of gas annually," the company said.

A consortium of Indian Oil, Oil India and a unit of Bharat Petroleum had in March signed a similar agreement with Rosneft to buy a 23.9 per cent stake in the Vankor oilfield for about $2 billion.