A project to improve train links with central London will create more than 2,000 jobs.
Engineering and technology firm Siemens has been awarded a £1.6bn contract to build new carriages for the Thameslink rail line which links Bedford to Brighton and goes through much of southwest London.
The firm will build 1,140 carriages which will enable the line to carry its first 12 carriage trains and increase its capacity by up to 29 per cent.
The line goes through 50 stations including Sutton, Hackbridge, Carshalton and Wimbledon. The first carriages will be on the tracks in 2016 and the project will be finished in 2018.