Thousands of Canadian pensioners are relying on the high-speed line through Kent to protect their retirement income after Eurotunnel was outbid by a Transatlantic rival.

The Government netted £2.1bn from selling a 30-year concession to run High Speed 1 to Borealis Infrastructure and Ontario Teachers' Pension Plan.

Borealis invests in transport infrastructure projects for OMERS - Ontario Municipal Employees Retirement System - one of Canada's largest pension plans. Between them, OMERS and Teachers hold £90bn of assets for nearly 700,000 active and retired employees.

Borealis saw off a rival bid from Eurotunnel/Goldman Sachs to take over the line from publicly-owned London and Continental Railways. The consortium will be responsible for St Pancras International, and international stations at Ashford, Ebbsfleet and Stratford.

John Keefe, of Folkestone-based Eurotunnel, said the operator was disappointed but pragmatic.

"We didn't win exactly what we wanted but it's not a terrible tragedy because we've got a significant boost to traffic without having to spend very much - and we've still got money in our war chest."

HS1, which cost £5.6bn, is used by Eurostar trains to Paris and Brussels and Southeastern high-speed domestics. New operators such as DB German Railways are expected to compete with Eurostar from 2012 or 2013, boosting Eurotunnel's revenue from tunnel access charges.

Sim Harris, managing editor of Rail News, said the change of ownership would make little difference to Kent passengers - unless something went wrong. "Borealis will have a back-seat role. Their job is to make sure the line is maintained properly and to work with operators to make sure they have the pathways they need," he said. The consortium had got a good deal because it was paying only 40 per cent of the capital cost. "I think an accountant would say that's not bad."