British Airways has increased its shareholding in Iberia from 10.1% to 13.15%.
It has bought 28,745,767 shares of the Spanish airline at an average price of €2.34 per share.
The airline, which abandoned takeover plans for Iberia last November, said it was planning further investment in the airline.
BA chief executive officer Willie Walsh said: “This purchase reflects the strategic importance we attach to our relationship with Iberia and our continued confidence in its management. We will consider further opportunities to increase our stake.â€
By Bev Fearis
