At the National Commodity and Derivatives Exchange, refined soya oil for delivery in July declined 95 paise, or 0.15 per cent, to Rs 631.50 per 10 kg with an open interest of 43,380 lots.
Similarly, the oil for delivery in August shed 60 paise, or 0.10 per cent, to Rs 629.70 per 10 kg in 35,020 lots.
Analysts said offloading of positions by traders owing to sluggish demand in the spot market against adequate stocks position on increased supplies from producing regions mainly led to the decline in refined soya oil prices at futures trade.