The failure of a circuit breaker at the Reuters Global Technical Centre in London (GTC-L) yesterday afternoon caused disruption to approximately 25% of the systems supported from the building riser that was affected. Approximately one hour after the first incident a second riser failed due to overloading, which meant that two out of the four risers supporting GTC-L lost power.

Reuters says all relevant support and development staff "have been working round the clock on the recovery of our systems". Power was eventually restored at midnight, although residual issues continue to afflict performance.

By 11 am GMT this morning, Reuters Transactions services were back in business, although the vendor warned that some London customers may be experiencing service issues for their Dealing 3000 Direct service.

Reuters is also working to ensure that there were no gaps in news storage and time series data during the incident. The vendor says that all historical news should be restored by market open on Thursday.

And while real time data outside of Europe is available, issues remain with European Exchange data sourced from the Integrated Data Network (IDN). Tuesday's close and subsequent net change for all European Exchange data will be suspect, says Reuters, and historical data will be delayed for the foreseeable future until work to restore this is completed.

End of day prices through Datascope and closing prices for S&P and FTSE indices should also be approached with caution, says Reuters.

In a statement, the news and information group says: "Reuters continues to work on restoring all services and products to our customers. This is being pursued with the utmost urgency."