Derby-based train manufacturers Bombardier have announced it has secured an order worth £60 million.
The order from Southern and Porterbrook Leasing is for 40 Bombardier Electrostar cars to operate on services in London and the South East.
In December 2011, Bombardier received an order for 130 new Electrostars from Southern which are currently in production at the Derby factory.
Southern's Managing Director, Chris Burchell, said: "This good news is timely as the first carriage of the original 130 ordered is close to completion. These additional 40 carriages will provide much needed capacity on some of our busiest routes."
The first of a 130 new carriages for Southern trains have come off the production line in Derby.
They have been built by Bombardier at its site in the city and will be used to ease over-crowding on key routes south of London. Bombardier secured the £188 million deal in September last year.