Seven people died in the Potters Bar rail crash in May 2002

The firm was named preferred bidder on the routes in June 2003, and the decision has now been confirmed.

One of the contracts is to replace track on the Potters Bar stretch of line in the London North East area.

BBC Transport Correspondent Simon Montague says it means Jarvis will be working on the same stretch of line where the fatal 2002 accident occurred.

The other contracts are for switches and crossings for all of Scotland, and for switches and crossings in the London North East region.

The company has been awarded five-year contracts to carry out the three areas of work.

This is separate from Jarvis's former day-to-day rail maintenance work, which it handed over to Network Rail last October.

Under investigation

Seven people were killed at Potters Bar station in Hertfordshire in May 2002, when the rear coach of the train heading for King's Lynn in Norfolk was derailed.

It is believed to have happened when a four-carriage West Anglia Great Northern passenger train, travelling at 96mph, went over a faulty set of points.

Poor maintenance work has been blamed for the crash, though the root causes have yet to be established.