Network Rail has admitted health and safety failings over the 2002 Potters Bar train crash
The track and station owner told Watford Magistrates' Court it will plead guilty to proceedings brought by the Office of Rail Regulation (ORR) over the condition of tracks at the disaster site.
Six passengers and a pedestrian were killed when a West Anglia Great Northern express train travelling from London to King's Lynn derailed at a faulty set of points in Hertfordshire on May 10 2002.
Peter Palfrey, chair of the bench at Watford Magistrates' Court, referred the case to St Albans Crown Court for sentencing on March 30 at 10am.
Prashat Popat QC, representing Network Rail, said the organisation will plead guilty to failings surrounding the installation, maintenance and inspection of adjustable stretcher bars, which keep the moveable section of a track at the correct width for train wheels.
During a brief hearing, Mr Palfrey said: "In this case we have decided that the charge is so serious we cannot give punishment at this court."
The ORR launched proceedings over alleged breaches of health and safety law following the conclusion of an inquest into the disaster last year.
While the maintenance company involved was Jarvis, the overall responsibility for the track rested with Railtrack whose functions were taken over by NR in October 2002.
Six passengers - Austen Kark, Emma Knights, Jonael Schickler, Alexander Ogunwusi, Chia Hsin Lin and Chia Chin Wu - were killed in the crash in Hertfordshire on May 10 2002.
The seventh victim, Agnes Quinlivan, was walking nearby and died after she was hit by debris.
More than 70 other people were injured when the 12.45pm King's Cross to King's Lynn train crashed as it reached Potters Bar station, where it was not due to stop, at around 1pm.
The inquest concluded that a points failure was to blame.
The Crown Prosecution Service initially ruled out launching criminal proceedings, in 2005.
Speaking outside court, Network Rail repeated its intention to plead guilty but said the railways were now safer than ever.
"We have indicated a guilty plea today as Network Rail took on all of Railtrack's obligations, responsibilities and liabilities when it took over the company in October 2002, some five months after the accident," a spokeswoman said.
"The railway today is almost unrecognisable since the days of Railtrack and the Potters Bar tragedy of 2002.
"Private contractors are no longer in control of the day-to-day maintenance of the nation's rail infrastructure since Network Rail took this entire operation, involving some 15,000 people, in-house in 2004.
"All of the recommendations made by both the industry's own formal inquiry and the health and safety investigation have been carried out."