Regions

Last week, a three hour halt occurred during midday during trading at NASDAQ OMX Group. The latter said that the trading outage was caused by a software bug and other internal technology issues. The software bug was triggered by problems at NYSE Euronext's Arca exchange. This led to a failure in its key backup system, said the exchange operator on Thursday.

Nasdaq said that it was deeply disappointed regarding the three-hour halt last August 22. The exchange operator pointed out that the problems in connection were between its system and rival's NYSE electronic exchange Arca. Nasdaq took ultimate responsibility for the trading outage.

Bob Griefeld, Nasdaq's CEO said in an interview, "Our backup system did not work. There was a bug in the system, it didn't fail over properly, and we need to work hard to make sure it doesn't happen again."

NYSE parent's New York Stock Exchange refused to give comments.

Nasdaq said that it took 30 minutes to resolve the issue and around three hours more to test and evaluate scenarios. This was to ensure that the market reopens trading in a fair and orderly manner.