Oil and Natural Gas Corp (ONGC) has paid just over $1.25 billion for a 15 percent stake in Russian oil major Rosneft’s Vankor oil field, a source with direct knowledge of the deal said. ONGC expects to get more than 3 million tonnes of oil a year (between 66,000 and 70,000 barrels per day) from its holding in the huge Siberian oil field, the source told Reuters on condition of anonymity. Rosneft earlier announced the deal to sell the interest in Vankor, a key source of supply to markets in the Asia-Pacific. Chief executive Igor Sechin said that talks with China’s CNPC on a Vankor stake were continuing.