Bombardier has won a £1 billion contract to supply the trains for the cross-London Crossrail project.
The deal involves the supply, delivery and maintenance of 65 new trains and a depot at Old Oak Common between Harlesden and Acton. This is expected to support 760 UK manufacturing jobs and 80 apprenticeships.
The Department for Transport said just under three quarters of the amount spent on the contract would stay in the UK economy.
Dr Francis Paonessa, managing director of Bombardier Transportation UK, said: "This is a resounding endorsement of our proposed Bombardier Aventra train for Crossrail, which has proudly been designed and developed in the UK as an iconic and world-technology leading train for London.
"Today's decision is a credit to the efforts of our entire workforce in the UK, including our 1,600 strong Derby-based design, engineering and manufacturing team who form a global centre of excellence for the rail industry, as well as our outstanding maintenance teams who support train operators right across the country and particularly in London as demonstrated during the London 2012 Olympics."
Business Secretary Vince Cable said the decision gave the Midlands a boost and represented a "real vote of confidence in British manufacturing".
He added: "The government has been working hard with industry to support the UK rail supply chain to maximise growth opportunities through contracts like this."
The Crossrail service – which will run from Maidenhead and Heathrow Airport in the west to Abbey Wood and Shenfield in the east – is due to open in 2018.