Spanish construction group Ferrovial said Wednesday it had agreed to sell a stake in London's Heathrow airport to Chinese firm CIC International.

Ferrovial said in a statement it was selling a 5.72-percent stake in FGP Topco, the holding company that controls the airport, to CIC International's subsidiary Stable Investment Corporation, for the equivalent of 319 million euros ($415 million).

It said Stable had also acquired shares from other shareholders in Topco to take its overall stake in the airport to 10 percent.

Topco controls Heathrow Airport Holdings, formerly known as BAA, the British firm that manages Heathrow and other British air hubs.

The transaction reduced to 44 percent Ferrovial's stake in Topco, which will fall to 33.65 percent when it concludes its earlier-announced sale of a stake to the investment fund Qatar Holding, the company said.

"We will continue to work with the new shareholders and with existing shareholders to ensure that Heathrow Airport Holdings Ltd. retains its position as one of the best infrastructure assets in the world," said Ferrovial's chief executive Inigo Meiras in the statement.

Ferrovial's shares rose 1.54 percent on the Madrid stock exchange after Wednesday's announcement.

Ferrovial said on Tuesday that its net profits rose to 488.5 million euros in the first nine months of 2012, fed by international markets, with earnings growing particularly strongly at Heathrow.