TORONTO - The Toronto stock market was back in business Thursday morning after technical problems forced it to shut down for a day, the exchange's chief executive promising to try to prevent such a thing from ever happening again.
  
"I would like to apologize to our customers for the disruption that the halt in trading caused yesterday," Tom Kloet, CEO of market operator TMX Group (TSX:X) said in a statement.

"I would also like to assure investors that all efforts are being made to ensure that such a disruption in trading does not happen again."

Normal trading resumed at the 9:30 a.m. ET bell Thursday, with no problems reported in early action, after TMX Group put the brakes on trading early Wednesday when it discovered a problem with its data feed.

It was the first time the Toronto Stock Exchange has been shut down for a whole day due to a technical glitch and it riled many on Bay Street, who were forced to either stay out of the stock market or find alternatives venues on which to trade.

"It's certainly an issue that is concerning and something that we take very, very seriously," Kloet told Business News Network.

"That said, it's important for us to put this in perspective. Other exchanges around the world do deal with technical outages," Kloet said, noting that the London Stock Exchange was down for seven hours one day in September due to technical problems.

"Exchanges run a complex set of networks around two very important areas, both the trade matching engine and the data dissemination business and it's really important that both work. And the focus of our attention yesterday was to make sure that our data could be evenly distributed to all market participants."

Investors didn't appear to be returning to the markets with much optimism Thursday -- the main index fell 304 points or 3.5 per cent at 8,420.

The problem was not with the software that actually handles the buying and selling of stocks -- the TSX's relatively new Quantum engine -- but rather with data feeds that send information about what's going on in the current session's trading to investors.

Since some weren't getting accurate information, the TSX decided to level the playing field and shut down trading for everybody.

About 18 minutes of actual trading did take place -- representing about 28,000 stock trades -- Wednesday before the halt.

What caused the problem was a "network firmware issue," a glitch with the software that runs the hardware across which trading data flows.
  
It was the third major glitch this year at the TSX.

On Oct. 10, trading was halted on 38 stocks for more than two and a half hours because of a technical problem. Jovian Capital Corp.'s Horizons BetaPro exchange traded funds weren't able to trade at the open on Oct. 14.

And on Nov. 7, trading on the TSX didn't start until nearly 10 minutes after the scheduled opening time. The TSX said that problem originated at services provided by Standard and Poors in New York.