A key bidder has dropped out at the last minute from a privatisation competition that could mark a radical step forward for the handing of US roads to the private sector.

According to people involved, banks that were contracted to finance a bid by a consortium of Australia’s Macquarie and Cintra, the Spanish toll road operator, to run the Pennsylvania Turnpike are now financing other bids. The move signals clearly the Macquarie consortium has dropped out of bidding for the US’s longest toll road, for which bids have to be submitted on Friday.