UPDATE Borsa Italiana, the Milan trading venue owned by the London Stock Exchange, halted trading this morning after problems on its price data feeds.

As of 15.50 CET (14.50 UK time), Borsa Italiana trading has reopened, after most of its platforms were closed all morning and the derivatives platform spent nearly four hours offline. The results of an investigation into the problem, which this morning was described by Borsa Italiana as “a technical issue on the price information systems”, have not been disclosed. 

Borsa Italiana runs on the TradElect system, based on Microsoft .Net and written in C#, recently dumped by the LSE in favour of Millennium Exchange, written in C++ and based on Novell SUSE Linux servers. The LSE has also been experiencing price data feed problems on its own replacement system, but these issues are thought to be unrelated.

It has not been confirmed whether TradElect is the source of the Borsa Italiana problem. In 2008, an all day outage in London on TradElect angered traders, prompting the LSE to start moving to the new Millennium Exchange system. The LSE confirmed to Computerworld UK that it intends to scrap TradElect on Borsa Italiana, and move to Millennium, by the end of this year.

This morning on Borsa Italiana, the opening auction reportedly failed to take place, which meant opening prices for stocks were not set.

“Borsa Italiana informs that all markets are suspended,” the Milan exchange said on a live service portal for clients at 12.23pm CET (11.23am UK time). Restoration operations for the data feeds, called DDMPlus, were “ongoing”.

A number of large price data vendors working with London Stock Exchange have also been experiencing problems in the capital, in what are thought to be unrelated circumstances. A number of those providing LSE share prices from the Millennium Exchange system have been displaying blank or incorrect London stock prices since the launch on 14 February.