* Network Rail, Jarvis charged with health, safety breach
* Companies face unlimited fines if found guilty
By Karen Foster
LONDON, Nov 10 (Reuters) - Britain's rail operator Network Rail and rail maintenance company Jarvis will be prosecuted over the 2002 Potters Bar rail crash that killed seven people, the country's rail regulator said on Wednesday.
The Office of Rail Regulation said it had begun criminal proceedings against the two companies for breaches of health and safety law, which caused the derailment north of London in May 2002.
The accident happened when a high-speed train on its way to King's Lynn, Norfolk, from King's Cross in London came off the tracks and a carriage ploughed into Potters Bar station.
Network Rail and Jarvis are both being charged for failing to provide and implement sufficient training, standards, procedures and guidance for the installation, maintenance and inspection of adjustable "stretcher" bars on the rail line.
Stretcher bars keep the moveable section of track at the right width for the train's wheels. A Health and Safety Executive report in May 2003 found several nuts that held the stretcher bars were missing and components were in poor condition.
The companies could face unlimited fines if found guilty.
"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," said Ian Prosser, director of rail safety at the regulator.
At the time of the accident, the infrastructure controller for the national rail network was Railtrack Plc, which was taken over by Network Rail in October 2002.
Jarvis, which was maintenance contractor for the Potters Bar area of the national network in 2002, had its shares delisted and went into administration in March this year after failing to secure fresh capital from its lenders.
Transport Secretary Philip Hammond told the BBC on Wednesday that if the regulator had found prima facie evidence of wrongdoing, it was right to launch a prosecution.
The prosecution follows the conclusion of the inquest earlier this year, in which a jury returned verdicts of accidental death for all the fatalities.
Network Rail said the network system had changed since the Potters Bar accident and private contractors no longer controlled day-to-day maintenance.
The case is due to go to court on Jan. 7. (Additional reporting by Sarah White; Editing by David Holmes) ($1=.6256 Pound)