At the National Commodity and Derivatives Exchange, refined soya oil for delivery in January month edged higher by Rs 1.05, or 0.16 per cent, to Rs 655.50 per 10 kg with an open interest of 51,695 lots.
Similarly, the oil for delivery in February contract inched up by 20 paise, or 0.03 per cent to Rs 650 per 10 kg in 73,330 lots.
Analysts said speculators built up fresh positions after pick up in demand in the spot market against restricted arrivals from producing belts.