At the Multi Commodity Exchange, mentha oil for delivery in August fell by Rs 9.20, or 0.98 per cent to Rs 928.50 per kg in a business turnover of 390 lots.
Likewise, the oil for delivery in far-month September moved down by Rs 6.90, or 0.73 per cent to Rs 942 per kg in 27 lots.
The weakness in mentha oil prices at futures trade was mostly attributed to profit-booking by participants at existing levels amid fall in demand from consuming industries against adequate stocks position, analysts said.