Six people died when a London to King's Lynn train derailed after a points failure on 10 May 2002, with a pedestrian also killed.
The case will be heard at Watford Magistrates' Court in January.
In 2005, the Crown Prosecution Service (CPS) said there was no realistic prospect of conviction for gross negligence manslaughter against any individual or corporation in relation to the crash.
The ORR said it had been told last month that the CPS saw no grounds to reconsider its decision.
However, after a Health & Safety Executive investigation, which blamed poor maintenance, the regulator's director of rail safety Ian Prosser said there were now grounds for a prosecution under the Health and Safety at Work Act.
"I have decided there is enough evidence, and it is in the public interest, to prosecute Network Rail and Jarvis Rail for serious health and safety breaches," he said.
"For the sake of the families involved, we will do all we can to ensure the prosecutions proceed as quickly as possible."
The ORR said the charge resulted from "failure, as infrastructure controller for the national rail network, to provide and implement suitable and sufficient training, standards, procedures and guidance for the installation, maintenance and inspection of adjustable stretcher bars (part of the points)".
Railtrack was in charge of rail infrastructure at the time of the accident, but it was subsequently placed into administration by then Transport Secretary Stephen Byers, and its responsibilities were taken over by Network Rail in October 2002.
Network Rail said in a statement that the modern railway was "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 NR 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.
"Today the railways are safer than they have ever been, but our task remains to build on that record and always to learn any lessons we can to make it ever safer for passengers and those who work on the railway."
Jarvis Rail, the maintenance contractor for the Potters Bar area at the time of the crash, went into administration in March 2010 but faces a charge under the same section of the act.