The London Stock Exchange restored full connectivity today at four o'clock - just half an hour before the scheduled close.

A spokeswoman for LSE said: "Trading resumed at four o'clock and we will close as normal at 4.30. We work with a number of suppliers so cannot speculate at this stage as to what caused the problems."

Today should have been one of the biggest trading days of the year following yesterday's $200bn bailout of Freddie Mac and Fannie Mae by the US government. UK banks and mortgage providers with investments in the US mortgage markets should have felt the benefit of investors' improved confidence.

After a miserable few months for share dealers and banks, many were expecting to cut their losses today. Outages at the exchange are not unknown but to lose an entire day's trading is far more damaging, especially on a day like today.

City veteran David Buik told AP: "For the life of me, I cannot understand why the LSE system is not run in duplicate. So much and so many clients rely on the LSE's durability. They cannot afford to be let down." He said European clients were furious at the lost day. ®

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