Indian Oil Corp bought 3 million barrels of Russian Urals for June loading in a tender, trade sources said on Tuesday.
IOC stepped up purchase of Russian grade as Brent-linked grades become competitive against those priced on Dubai after the price spread between the two benchmarks narrowed.
IOC issued second tender for sour crude to close on April 19.
IOC last bought 1 million barrels of Urals each to load in May and March.