The British government is selling "High Speed 1," which has a 30-year concession to run a 110-kilometre (70 mile) railway linking London and the Channel Tunnel, to help cut its budget deficit.
The "GB Speedrail" group, already consisting of Eurotunnel Goldman Sachs Infrastructure Partners and M&G's Infracapital, has been joined by two financial backers, Britain's Universities Superannuation Scheme, and France's Caisse des Dépôts et Consignations, a spokesman for the group said.
"We will make an indicative bid today," the spokesman said.
The five-strong group is vying with at least two rival teams.
One is made up of Morgan Stanley Infrastructure, 3i Infrastructure and Abu Dhabi Investment Authority.
A second Canadian partnership has allied Borealis, the infrastructure investment arm of Ontario
Municipal Employees Retirement System with Ontario Teachers' Pension Plan.