Trading on the LSE’s electronic platform was shut down this morning on one of its busiest days of the year.

The timing of the shutdown is unfortunate for the LSE, which is facing increased competition from rival trading platforms such as Turquoise, a Europe-wide platform set up by a number of the world’s biggest investment banks.

Another rival, Chi-X, claims to have taken over 15 percent of trading in FTSE 100 stocks recently.

To counteract the challenge, the LSE slashed trading fees at the start of this month in response to a partial launch of Turquoise, which is not due to start trading proper until October.

Today’s debacle was thought by the BBC’s Business Editor Robert Peston, to have serious consequences for the exchange. A great deal of money was tied up in the system, money that could not be used in a rapidly rising market.

With shares in the London Stock Exchange hitting the dizzy heights of £13.92 ($27.56) — Nasdaq’s offer was £12.43 — the exchange is now on the reserve list for the Footsie 100.

If it’s promoted to that elite squadron, its stock would be picked up by all the tracker funds leading to further gains in value. It’s an enviable prospect and would probably ensure the hard-pressed exchange some respite from the constant challenges it has faced in recent years.

As if to emphasise the point, the LSE has just upgraded its technology platform. The new system allows trades to be executed in full in just 10 milliseconds and allows companies a much easier experience for trading in shares and other instruments.

Called TradElect, the new system is one in the eye for bankers’ darling, Project Turquoise, which is yet to be launched.

Here’s how the LSE describes TradElect :

TradElect, the Exchange’s brand new trading system is up and running. TradElect brings unprecedented levels of performance, enhanced functionality and new services to our markets whilst maintaining our exemplary record for reliability.

It allows our customers to trade on one of the fastest, most reliable and technologically advanced equity markets in the world.

Its introduction marks the final and most significant phase of the Exchange’s four-year system upgrade project – known as Technology Roadmap (TRM) – and now delivers a range of key functional and technical enhancements including;

* Increase the speed and efficiency of trading
* Provide the framework for the rapid development of new markets and asset classes
* Enhance the market structure to better support order routing, settlement and clearing
* Extend functionality for order handling, quote management and trade reporting.

These are surely the good times for the LSE and its doughty chief executive, Clara Furse, and chairman, Chris Gibson-Smith.

Recently we reported that London Stock Exchange chief executive, Clara Furse, attacked new rival on the block, Project Turquoise — a trading platform being created by seven investment banks — as non-viable.

Furse claimed the rival banks’ platform will not be able to compete with the LSE’s 4p fee from £1000 worth of shares purchased.

Project Turquoise responded, “We are very much on track to be up and running and reduce the total cost of trading for those who buy and sell shares”.

Soon, however, PT’s seven founders, Goldman Sachs, Merrill Lynch, UBS, Citigroup, Morgan Stanley, Deutsche Bank and Credit Suisse, will be joined by another, BNP Paribas of France. Already a formidable alliance, Turquoise now looks a true heavyweight.

Final details of the technology systems to power the platform are close to agreement. If the final result is cheaper trading — and it’s hard to imagine them coming in at a higher price — this will give the LSE a real run for its money.

The kind of complacency that saw London’s Liffe passing to Euronext right under Clara Furse’s nose, must not be repeated here.

The big banks rival to the London Stock Exchange, Project Turquoise, steps up a gear with the appointment of EuroCPP as its clearing and settlement system.

The new European share trading platform is the baby of seven investment banks, including Merrill Lynch, Citigroup and Goldman Sachs.

Project Turquoise is set to begin trading in all European shares by the end of this year, lowering business prospects for the LSE.

The group has yet to appoint a chief executive, however.