The Office of Rail Regulation (ORR) said it had started criminal proceedings against NR for a breach of health and safety law that caused a Virgin Trains Pendolino train to derail on February 23 2007.
Passenger Margaret Masson was killed and 86 people were injured, 28 seriously.
Earlier investigations as well as last year’s inquest into the death of Mrs Masson concluded that the derailment was caused by a poorly maintained set of points.
NR is facing a charge under the 1974 Health and Safety at Work Act.
The ORR said: “This results from the company’s failure to provide and implement suitable and sufficient standards, procedures, guidance, training, tools and resources for the inspection and maintenance of fixed stretcher bar points.”
The stretcher bars hold the moveable rails a set distance apart when the points are operated.
ORR safety director Ian Prosser said: “Following the coroner’s inquest into the death of Mrs Masson, I have concluded that there is enough evidence, and that it is in the public interest, to bring criminal proceedings against NR for a serious breach of health and safety law which led to the train derailment. The ORR will do everything it can to ensure that the prosecution proceeds as quickly as possible.
“The railway today is as safe as it has ever been but there can be no room for complacency. The entire rail industry must continue to strive for improvements to ensure that public safety is never put at risk.”
The first hearing is due to take place at Lancaster Magistrates’ Court on February 24.
The case is almost certain to be committed to a Crown Court.
The maximum penalty a magistrates’ court can impose for the offence is a fine of £20,000.
Last year, NR was fined £3m at St Albans Crown Court after admitting safety breaches involving a set of points which led to a derailment at Potters Bar in Hertfordshire in May 2002. Seven people were killed.
NR had assumed responsibility for the crash from its predecessor rail infrastructure company, Railtrack.
The ORR delayed its decision on legal action over Grayrigg until the inquest into Mrs Masson’s death concluded last November and after the Crown Prosecution Service had said it would not prosecute.