London Stock Exchange problem was network change mix up

The two-hour disruption affected the Turquoise trading system

The two-hour disruption experienced by the London Stock Exchange's Turquoise multilateral trading facility (MTF) this week was the result of an error by a contractor when making a small network change, according to a source close to the company.

Speculation has been rife that a contractor was to blame when the Turquoise network went down last Tuesday, 2 November. A source close to the exchange said that a contractor had mistakenly put a network change into the live environment rather than the test environment.

"It was pure human error," said the source.

The London Stock Exchange declined to comment. The migration of the London Stock Exchange to MillenniumIT, planned for next month, will now be put back following the disruption.

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