National Commodity and Derivative Exchange (NCDEX) is unlikely to go ahead with onion futures trading while it was set to launch spot trading in coffee and maize."We have received approval from the Forward Market Commission for futures trading in onion, but have decided to stay away," P H Ravikumar, managing director, NCDEX, told PTI."Onion, apart from being a highly politicised commodity, was difficult to store," Ravikumar added.Traders said onion prices, which had shot up sharply a few months ago, had tumbled on mounting arrivals and subdued export demand and were expected to remain weak for the next few months.Wholesale price in the country's largest onion trading hub, Lasalgaon in Maharashtra, fell to its lowest level at Rs 365 per 100 kg from a peak of Rs 1,951 on October 1.Onion prices had slipped following the government's announcement of an action plan to check rising prices and an increase in onion supply, commission agents said. Onion prices are likely to drop as output is projected to go up 14% in 2007-08 with the area under the crop likely to increase in the on-going kharif season.