KARACHI, Feb 25: Trading at the Karachi Stock Exchange was halted in the second session on Friday, for 45 minutes, which triggered a series of stories among the market participants. But the stock exchange came up with an explanation in the evening to allay investors' concerns, saying that the trading halt was "due to a technical problem".

The Exchange stated in a press release: "In the pre-open session of the afternoon, almost all of the Trading Workstations (TWS), out of 1,000 plus, exercised an option to globally cancel all their queue-in orders. The situation created unprecedented queues and resulted in non-responsive situation of TWS.

Being TWS inactive, the operators started exercising this option repeatedly, which in turn put more messages in queue, resulting in temporarily choking the trading system.

As recourse to this situation, the Exchange suspended the market in order to enable the system to flush out the queue-in cancelled orders." The Exchange said it was analyzing the event and carrying-out various simulation exercises, in order to find a solution, to avoid recurrence of the problem.