The Hong Kong stock exchange said Wednesday its website had been hit by "malicious hacking", forcing trading in at least seven companies that issued price-sensitive information to be suspended.
Firms that were suspended from trade include blue-chips banking giant HSBC and Hong Kong flagship carrier Cathay Pacific, after the technical problems were reported on the bourse's website shortly after the midday break.
Charles Li, the stock exchange's chief executive, said initial investigation found computer hackers had launched an attack on its website.
"We are working on it and hopefully we can bring it back online as soon as we can," he told a news conference later.
The exchange said its other systems were not affected and trading in its securities and derivatives markets continued to operate normally.
Companies that were suspended from trading included HSBC which announced the sale of its United States credit card and retail services business as part of an overhaul to streamline its global operations.
Cathay meanwhile reported its 2011 half-year earning results, with net profit tumbling almost 59 percent compared to a year earlier.
Hackers attacked the Zimbabwe stock exchange website on Friday, forcing a shutdown of the site and hampering traders monitoring performance on the 79-company bourse.
Explore further: Turkey still hopes Twitter will open local office