The Caisse de dépôt et placement du Québec (CDPQ) is among the shareholders selling another 10% stake in London’s Heathrow Airport to French private investment firm Ardian.

Ardian announced that it has entered into a binding agreement to acquire the stake in FGP Topco (TopCo), Heathrow’s holding company, from Ferrovial SE and other TopCo shareholders, including Quebec City-based CDPQ. The deal follows Ardian’s December 2024 acquisition of a 22.6% stake in TopCo from CDPQ, Ferrovial, and the U.K.-based Universities Superannuation Scheme pension fund.

With the earlier deal, Ardian became Heathrow’s largest shareholder. The latest purchase will increase Ardian’s ownership stake to 32.6%.

Mathias Burghardt, head of Ardian’s France and infrastructure businesses, said the acquisition reaffirms the firm’s commitment to investing in essential U.K. infrastructure.

“Since we became the largest shareholder of Heathrow in December, the airport has continued to perform strongly with traffic reaching 83.9 million passengers in 2024,” he said. “We are delighted to be working with our fellow shareholders, the Heathrow management team and the U.K. authorities on our shared ambition to deliver sustainable growth of this iconic infrastructure. Investment in Heathrow will deliver economic benefits across the entire country.

Burghardt said the transaction is a further sign of Ardian’s commitment to investing in essential U.K. infrastructure.

The transaction is subject to the right of first offer (ROFO) provisions outlined in TopCo’s shareholders’ agreement and articles of association. Completion of the acquisition also depends on regulatory approvals.

Ardian invests in Canada and has an office in Montreal.