Virgin Trains and French rail operator SNCF are to jointly bid to run high-speed trains on the HS2 network.
The companies announced that they will enter the competition for the West Coast Partnership franchise, which will include services on the existing West Coast route from 2019 and initial HS2 trains between London and Birmingham from 2026.
If the bid is successful it would increase the proportion of Britain's rail network run by overseas operators.
Half of the partnership would be owned by Stagecoach, with SNCF taking a shareholding of 30% and Virgin 20%.
Virgin Trains co-chairman Patrick McCall said: