HS2 high-speed rail services will be run by the same operator as the West Coast Main Line, the Government has announced.
The new franchise - the West Coast Partnership - will cover services on the west coast route from 2019 and running the initial high-speed trains between London and the West Midlands from 2026.
The contract will run for the first three to five years of HS2's operation.
Transport Minister Andrew Jones said: "We are embarking on a new chapter in our modernisation of the railways and we need world-class expertise to deliver it.
"HS2 will be the backbone of Britain's railways, creating more seats for passengers on the West Coast and increasing capacity on the rest of the network.
"By combining the franchise we are ensuring we get the right people on board at an early stage to design and manage the running of both services in the transition stage.
"The new franchise will attract highly experienced companies, who have the right experience, which ultimately means a better deal for passengers - both now and in the future."
The West Coast Main Line is currently operated by Virgin Trains - a joint venture between Stagecoach and Virgin.
It is hoped that HS2 will reduce overcrowding on the existing network and generate economic growth across the country.
Phase 1, due to open in December 2026, will see trains travel at high speed between London and Birmingham before running on from Birmingham on the existing west coast line.
Sir David Higgins, chairman of HS2 Ltd, the company responsible for building the £55.7 billion railway, said the franchise announcement means the high-speed trains can "complement and enhance" existing ones.
He added: "I have always been clear HS2 will not be a standalone railway but fully integrated with the wider network. It will provide a new backbone for our railways, modernising services to better serve towns and cities up and down the country.
"Bringing on board a new partner to work with HS2 Ltd now will help ensure we are working towards the same goal."