German Asset Managers (Gamag), a fund management firm, is suing Eurex, the German derivatives exchange, for cancelling orders following the execution of a suspected irregular trade yesterday.

Gamag stands to make a heavy loss from the cancellation of orders. It started trading heavily in futures contracts when it saw the market falling, suspecting that a terrorist attack elsewhere had caused the rapid fall. The company said it has done its own investigations which show that no erroneous or illegitimate activity took place.