At the National Commodity and Derivatives Exchange, refined soya oil for delivery in October fell by Rs 3, or 0.46 per cent, to Rs 650 per 10 kg, with an open interest of 21,780 lots.
Likewise, the oil for delivery in November weakened by Rs 2.75, or 0.42 per cent, to Rs 654.50 per 10 kg in 58,040 lots.
Marketmen said trimming of positions by traders, triggered by adequate stocks position on higher supplies from producing regions in the physical market against subdued demand, mainly led to decline in refined soya oil prices at futures trade.