The London Stock Exchange has called an urgent meeting next week with price data vendors, in an attempt to solve the serious market stock price irregularities appearing on traders’ screens since the exchange launched its new trading software.

The meeting, taking place on Tuesday, will involve many of the major vendors that have been displaying incorrect and blank stock prices. They are expected to address the problems and potential short and long-term solutions.

Computerworld UK understands that several executives from within the “big four” – Thomson Reuters, Interactive Data, Bloomberg (which said it did not experience problems) and Morningstar – have places at the meeting, alongside top-level managers from medium and small data vendors.

SIX Telekurs, which has an extensive reference data portfolio, confirmed it too will attend the meeting. The LSE has not provided details of its plans.

The scheduled date for talks comes two weeks after the launch of the Millennium Exchange trading system, which marked a major shift of technology for the exchange, as it brought systems in house and dumped an outsourced Microsoft .Net, C# written system. The exchange’s new system is ultra low latency, and was written in C++ to run on a Novell SUSE Linux based datacentre.

Problems have been rife through the last two weeks. While trade messaging had initially been reported as stable at an average round trip latency of 125 microseconds – a market record – traders accessing data from third party vendors have reported both blank and incorrect prices.

Publicly, the LSE and the vendors insist they have been working together to solve the problem. But privately, the exchange is frustrated that the long 15 month testing window had not prevented vendor issues. Equally, the vendors said they feel the LSE also has work to do but that the meeting offers a real opportunity to get to the bottom of the issues.

It remains unclear whether the problem is with the LSE data feeds or with the vendors’ processing of the data. Market sources said they expected it to be a combination of both factors, suggesting that coding instructions were either misinterpreted or unclear in the first place.

Most of the vendors experiencing trouble have applied “workaround” fixes, but these are not necessarily permanent. Thomson Reuters and Netbuilder, which supplies the LSE’s own ProQuote data service, were among the first to apply a fix. SIX Telekurs and Interactive Data have taken similar steps.

But a number of those that have applied patches are still receiving angry inquiries from traders over incorrect data.

A rapid recoding exercise is taking place throughout the weekend across many industry participants. It may not be until they speak together on Tuesday that the root cause or causes of the problems are identified.

"This is crisis point now," said an experienced exchange market source. "It's got to be fixed."

Data issues reached a crunch point today, when a severe information problem knocked the entire equities exchange offline for four hours this morning, leading to LSE chief executive Xavier Rolet personally apologising for the problems. But it is not known whether the price feed was at fault, and the exchange offered no detailed technical explanation.