The London Stock Exchange (LSE), which is seeking to acquire The Toronto Stock Exchange, suffered a four-hour halt in trading today due to some technical glitch.

Trading was suspended just after the exchange opened at 8 a.m. (Greenwich time) and did not resume until 12.15 p.m.

We sincerely regret the inconvenience that today's disruption to trading has caused our customers, said LSE chief executive Xavier Rolet. “We have resolved the real time data dissemination issue and our UK cash equity markets have now resumed trading.”

The LSE would not say exactly what caused the error, but that it had something to do with its new “Millennium Exchange” trading system and that its technicians had to fix a “real time data dissemination issue.”

The exchange did not decide to extend trading hours in order to make up for the lost time.
Trading on the Borsa Italiana (which is also owned by the LSE) suffered a similar suspension of trading on Tueday (for 6 ½ hours) also due to computer error.

The LSE was widely criticized for the glitches.

Joshua Raymond, City Index market strategist, told reporters: At a time of uncertainty in the markets, where traders are having to keep on their toes with the situation in Libya, the last thing they need is an unexpected halt to trading.

In this day and age, you simply cannot afford not to have your technology in duplication, said David Buik of brokerage BGC Partners, speaking on Bloomberg television. If it's not foolproof, where is the alternative? he said.

Damien Reece wrote in the Daily Telegraph newspaper: “This is not just damaging to Rolet’s company and its reputation, handing a simple advantage to its rivals. It also makes a laughing stock of London as the world’s leading financial centre.”

Ironically, the FTSE-100 index closed 1.4 percent higher, despite a slew of negative economic and geopolitical news, including a downwardly revised UK GDP.