The London Stock Exchange (LSE) has been hit by an attack on its website that disrupted an alerts service used by more than 14,000 private investors for more than 48 hours.

Attackers set up hundreds of thousands of erroneous alerts - using a method similar to a denial of service attack - overloading the LSE website and disrupting the service for legitimate users.

The service sends alerts when a company in an investor's portfolio makes a stock exchange announcement or when a share price moves outside set parameters.

A spokesman said the LSE is investigating the attacks.

'We hope we have now fixed the problem. We apologise for the loss of the service,' he said.