The British government said Friday that Borealis Infrastructure and Ontario Teachers' Pension Plan teamed up to win a 30-year franchise to operate the 68-mile (109 kilometer) line.
The government will continue to own the line, associated infrastructure and land.
The franchisees will receive revenue from access charges paid by train companies using the line. The principal user now is Eurostar, operating services to Paris and Brussels.
Germany's Deutsche Bahn has also announced an interest in starting high-speed services between Germany and London.