The probe will look at who owns infrastructure like ports, airports, energy and water networks, and car parks. Schools and hospitals will not be included.

OFT officials described the investigation as a “stock-take of ownership and control across economic infrastructure in the UK.”

Heather Clayton, Senior Director of OFT’s Infrastructure Group said: “Effective infrastructure is crucial to the performance and productivity of the UK economy, and the quality of life of UK consumers.

“There have been significant changes in ownership of infrastructure assets in both regulated and unregulated sectors of the economy over the past decade. We want to take this opportunity to step back and assess how these developments might have affected competition and consumers.”

The announcement will cause concern among private equity firms who raise funds for infrastructure deals.

The OFT is believed to be worried about the high levels of debt involved in many funding deals.

One PFI contractor told the Enquirer: “It’s never good news when the OFT get involved  – just look at the fallout from their investigation into construction bid-rigging.

“The use of private funds will be vital in infrastructure work as public spending grinds to a halt so it seems odd timing to cast a cloud over the whole system now.”