At the National Commodity and Derivatives Exchange, refined soya oil for delivery in August moved up by Rs 1.80, or 0.30 per cent to Rs 599.35 per 10 kg with an open interest of 2,10,560 lots.
Similarly, the oil for delivery in June contracts gained Rs 1.75, or 0.29 per cent to Rs 610.75 per 10 kg in 25,690 lots.
Market analysts said, speculators built up fresh positions due to pick-up in demand in the spot market against restricted supplies from producing belts, which led to the rise in refined soya oil prices.