At the National Commodity and Derivatives Exchange, refined soya oil for delivery in July went up by Rs 2, or 0.31 per cent, to Rs 639.25 per 10 kg with an open interest of 50,700 lots.
On similar lines, the oil for delivery in June contracts gained Rs 1.90, or 0.30 per cent, to Rs 632.30 per 10 kg in 9,030 lots.
Analysts said widening of positions by traders following rising demand in the spot market primarily kept refined soya oil prices higher in futures trade.