UK Transport Secretary Geoff Hoon has announced the biggest investment in Intercity trains for a generation.

Agility Trains has been selected as the preferred bidder for a £7.5bn contract to build and maintain a fleet of new Hitachi Super Express trains for the Great Western and East Coast Main lines. These will replace existing high-speed trains that are 20-30 years old.

Agility - a British-led consortium comprising of John Laing, Hitachi and Barclays - will make a significant investment as part of the contract. To build the trains, Hitachi, Agility Trains’ principal supplier, will establish a rolling stock manufacturing facility in the UK.

From feasibility studies to date, a shortlist of three suitable sites, located in Ashby de la Zouch in Leicestershire, Sheffield and Gateshead, has been drawn up, with all locations under active consideration.

The Hitachi Super Express fleet will comprise full electric, bi-mode and hybrid trains configured in 10 and five coach formations (26m coaches) delivering over 1m additional seats per year on the East Coast Main Line alone. Trains will be serviced, maintained and cleaned around the UK at five new train maintenance centres and several upgraded existing facilities.

For its part, the UK Transport Department is also in advanced negotiations with National Express East Anglia to provide 120 new carriages for the Stansted Express service from London Liverpool Street to Stansted Airport.

The preferred bidder for this order is Bombardier Transportation, which plans to build them in Derby.

The first of the new trains will enter service on the East Coast Main Line in 2013. Trains will enter full service from 2015, linking London with Cambridge, Leeds, Hull, York, Newcastle and Edinburgh, and linking London with the Thames Valley, Bristol and south Wales.