A Chinese sovereign wealth fund it had been hoped would back a new London hub airport has taken a 10% stake in Heathrow for a reported £450 million.

The China Investment Corporation (CIC), which was set up in 2007, has taken a 5.7% stake in Heathrow holding company FGP Topco from Spanish investor Ferrovial.

The remaining 4.3% has come from other investors in FGP Topco, according to the BBC.

The move by CIC comes after its first investment in the UK when it took an 8.68% stake in Thames Water in January.

Concerns have been raised about allowing foreign sovereign wealth funds to buy up national assets.

And the move by CIC is being seen as a blow to London mayor Boris Johnson’s hopes for a new airport in the Thames estuary, the investor having been expected to back the project.

Heathrow believes the investment suggests there is international confidence in the airport’s future as a major international hub.

Íñigo Meirás, chief executive of Ferrovial, said: “This sale of a stake in Heathrow Airport Holdings is a further part of Ferrovial’s investment diversification strategy.

“We will continue to work with the new shareholders and with existing shareholders to ensure Heathrow retains its position as one of the best infrastructure assets in the world.”

Ferrovial now has a 34% stake in Heathrow, down from the original 55% , and together Chinese Qatari, and Singapore government’s now control 40%.