The London Stock Exchange stopped trading this morning immediately after the opening auction, which experienced a major technical glitch.

The news comes at the end of the second week of trading on the exchange’s new Millennium trading system. Over the last fortnight, anger has been growing after large vendors that supply price data to the market continually experienced significant technical difficulties, including displaying entirely inaccurate and blank prices.

The LSE said the nature of the technical problem had not been established, though it told traders of a “market data issue”.

Best Bid Offers have been the subject of numerous difficulties throughout the last fortnight. Several vendors have highlighted to Computerworld UK that cancellations of orders had presented them with data effectively “stuck” in the system and blocking the correct transaction of other orders.

The problem was first announced at 7.54 this morning, when trades apparently cancelled on the system.

“The uncrossing trades that took place in the opening auction today are under investigation for potential cancellation,” the LSE said.

As of 8.59, the LSE said uncrossing and automatic trades from securities this morning will stand. Orders can be deleted, but not executed manually or automatically.

Millennium Exchange, the platform on the main venue of the LSE, is written in C++ language and running on Novell SUSE Linux-based datacentres. It offers data through the FIX and ITCH protocols.

Yesterday, the LSE experienced pricing problems on a separate platform, SOLA, for its derivatives exchange EDX. The day before, its Milan exchange, Borsa Italiana, was offline all morning following major issues on TradElect, the .Net-based system dumped in London.