Serco will maintain the track that is being used by Metronet to test air-conditioned tube trains

Metronet, the London Underground PPP company, has appointed Serco to manage the maintenance of a rail test track that will be used to test new air-conditioned tube trains.

Serco will be responsible for the Old Dalby test track near Ashfordby in Leicestershire, which has been leased by Metronet.

The new air-conditioned Tube trains will be introduced to one-third of London Underground鈥檚 network from 2009.

They are part of a 拢3.1bn upgrade of the Metropolitan, District, Circle and Hammersmith & City lines that is planned to increase capacity on these lines by over 40%.

Serco, which operates the Docklands Light Railway, was previously responsible for managing the test track before Alstom took over.

Metronet plans to electrify and use a 4km stretch of line that runs parallel to the main route which carries overhead electric cables.