A darkened television studio is seen at the offices of TMX Group, which operates the Toronto Stock Exchange, after the company announced it was shutting down all markets for the rest of the day after experiencing issues with trading on all its exchange platforms in Toronto, Ontario, Canada April 27, 2018. REUTERS/Chris Helgren

TORONTO (Reuters) - Canada’s largest stock exchange operator said on Saturday that the failure of data storage equipment caused an outage that shut down the world’s sixth-largest stock market for several hours on Friday afternoon.

TMX Group Ltd X.TO, which operates the Toronto Stock Exchange and smaller Canadian trading platforms, said it had fixed the error.

“All systems are ready for the start of business on Monday,” TMX said in a statement.

The outage drew concern from investors and financial institutions in Canada and around the globe because such shutdowns are relatively rare. When technical glitches occur, exchanges typically quickly switch over to back-up systems to prevent interruptions in trading.

In this case, a failure in a central storage appliance linked to both primary and redundant systems prevented fail over procedures from engaging, TMX said in its statement.

The company replaced a defective storage module, verified the integrity of data of all impacted databases and conducted a successful start-up validation of the entire trading system, TMX said.

The statement did not identify the vendor of the equipment that failed, though it said the outage was not the result of a cyber attack.

Canada’s last major trading outage occurred nearly a decade ago, when a system fault linked to data feeds shut down trading for a full day in 2008, including on the small-cap TSX Venture Exchange.