Virgin Rail will no longer run the West Coast Mainline service from December after losing out to rivals FirstGroup.
The route covers Scotland’s central belt as well London, the West Midlands and North Wales making it Britain’s busiest rail line.
First West Coast Limited will take over the franchise until 2026 although Virgin, who has run the service since 1997, can still launch a legal challenge against the decision.
Aberdeen-based FirstGroup has pledged to add 11 new 125mph six-car electric trains on the Birmingham-Glasgow route and provide more direct services between destinations.
The firm’s chief executive Tim O'Toole said: "Our bid also delivers value for taxpayers by returning premiums to the government underpinned by sustainable growth in passenger numbers and revenues from the utilisation of significant available capacity."
His Virgin counterpart Tony Collins added: “Naturally, we are all very disappointed by today’s announcement.
"We had submitted a strong, deliverable bid with emphasis on customer service which would have produced strong growth over the life of the franchise resulting in significant benefits for the taxpayer through generous premium payments to Government.
“Our efforts for the remaining four months of the current franchise will be to continue to offer a high quality service to our customers, who we would like to thank for their loyalty over the past 15 years, and hand over a healthy and efficient franchise to the new operator on 9 December.”