IAG also announced its intention to buy bmi, a Lufthansa division, in an attempt to boost profits at its Heathrow hub, the airline said on Friday.

British Airways and Iberia parent said it had reached an agreement in principle with bmi's German owner for the sale of the loss-making unit - the second-largest carrier at Heathrow - with any deal subject to due diligence and regulatory clearances.

"We're confident we can make a success of bmi and will look to expand our network, particularly our long-haul network through this deal," IAG's chief executive Willie Walsh told reporters, adding that IAG did not yet have exclusivity on any deal but believed its offer was more attractive than others Lufthansa had received.

Rival UK carrier Virgin Atlantic said it had made a bid for bmi and was still "working with Lufthansa".

IAG said it expects the purchase agreement to be signed in the coming weeks and for a transaction to be completed in the first quarter of 2012 with analysts put a £300 million price tag on the deal.