At National Commodity and Derivatives Exchange, refined soya oil for delivery in August declined by Rs 5.90, or 1.00 per cent to Rs 582.60 per 10 kg with an open interest of 2,37,300 lots.
Also, the oil for delivery in June contracts weakened by Rs 1.15, or 0.19 per cent to Rs 609.00 per 10 kg in 10,575 lots.
Market analysts said offloading of positions by participants, tracking sufficient stocks in the physical market against low demand mainly kept pressure on refined soya oil prices at futures trade.