Serco Group has been awarded the contract to manage the new 15-year franchise for the Caledonian Sleeper service by Transport Scotland.
From April 2015, the company will be responsible for operating all aspects of the Caledonian Sleeper including marketing, sales, passenger services, station facilities and fleet maintenance.
Some £100 million is to be invested in rolling stock, aimed at improving the customer experience. The new fleet is due to be introduced by summer 2018
The Caledonian Sleeper service will provide a vital connection between London and Aberdeen, Edinburgh, Fort William, Glasgow, Inverness and many other of Scotland's main towns and cities.
Rupert Soames, Serco Group chief executive officer, said: "With 3,000 Serco employees living and working in Scotland, we are tremendously excited to be delivering these new developments and meeting the vision of Transport Scotland."
Total revenue to Serco is estimated at £800 million over the 15-year period, of which around £18 million will take the form of franchise payments.