The deal should help ease the pain caused by Britain's decision earlier this year to award a key rail contract to Germany's Siemens AG
Canada's Bombardier, whose UK unit makes trains for use on Britain's railways, will build 130 new rail carriages for Southern, which runs services in south London, Surrey, Sussex and Kent, the Department for Transport (DfT) said on Wednesday.
The DfT is providing 80 million pounds towards the new deal, which will see new carriages enter service in December 2013.
This deal for more than 100 new carriages is great news for rail passengers and brilliant news for Bombardier and Derby, Transport Secretary Justine Greening said in a statement.
It lands Bombardier with a crucial train order and I look forward to Bombardier workers in Derby being among the winners of this important deal.
In June, Britain awarded a consortium led by Germany's Siemens
Earlier this month a committee of MPs said the process by which Britain decided to award the Thameslink deal would be subject to an official review.
(Reporting by Rhys Jones; editing by Neil Maidment)