Depreciatory transactions

N Ltd paid £600,000 for the shares of A Ltd, B Ltd and M Ltd. These companies had trades the same as part of N Ltd and little else in the way of assets. Immediately on purchase the trades were transferred into N Ltd at no cost. Some years later the subsids were disposed of and the Revenue denied a claim for losses on disposal of the shares as the transfer of trades was a depreciatory transaction. At around the same time, N Ltd sold its trade realising a large gain. It then continued to trade in other, previously comparatively minor areas. Can the costs of the subsidiaries now be set against the gain on the disposal of the trade? There is no chance at present of the shares in N (itself a subsidairy) being sold.
Philip Cragg