Network Rail's current renewals contractors are: Amey Seco, Balfour Beatty Rail, Carillion Rail, Jarvis, First Engineering and Grant Rail Group. Network Rail said it plans to save £150m over three years.
 
As well as saving money, Network Rail believes that the decision will accelerate the rate of efficiency.
 
Peter Henderson, director of projects and engineering, said: "We are confident that retaining a reduced number of track renewals contractors is the best way forward for renewals activity. As well as the core renewals work awarded under the existing contracts the opportunities to win elements of competitively awarded work remains, which will drive further efficiencies by offering growth in turnover for the highest performers." 

Starting in the New Year, Network Rail will begin a six-month review of their contractors, measuring their performance across a number of key areas that include safety records, volumes achieved, finishing jobs on time, unit costs and business behaviours.
 
A decision to select the four successful contractors will be made in mid 2007.