Balfour Beatty's rail infrastructure division had admitted breaching the Health and Safety at Work Act in relation to the broken rail which caused the crash, killing four people and injuring many others.

Jonathan Caplan QC, for the company, said: "Inevitably, some will perceive large companies as irresponsible if they seek to contest a financial penalty in the wake of a major accident.

"We don't believe that is the case here."

The company's failure to abide by safety rules was described by an Old Bailey judge last October as "one of the worst examples of sustained industrial negligence in a high risk industry I have ever seen".

Mr Justice Mackay said 750,000 passengers' lives had been put at risk due to the broken rail which eventually caused the derailment of a London-to-Leeds express on October 17 2000.

The 117mph derailment also left 102 injured.

A faulty rail at the crash site was identified 21 months before the crash but left unrepaired - although a replacement rail had been delivered and left alongside it for six months.

Balfour Beatty - responsible for track maintenance at the time - was fined £10 million and Network Rail £3.5 million for breaking safety rules before the crash. The companies were also ordered to pay £300,000 each in costs.

The trial judge had ordered that a verdict of not guilty should be entered on a charge of corporate manslaughter.