Qatar Airways and the owner of British Airways have vowed to strengthen ties after the Gulf carrier snapped up a 10 per cent stake in its European counterpart.

They have a close relationship as part of the oneworld alliance and Willie Walsh, the boss of International Airlines Group (IAG), said he was delighted that Qatar had become a "long-term supportive shareholder".

Qatar said it may consider raising its stake further, although it will be limited by an overall cap on non-EU ownership of European airlines at 49%.

Mr Walsh said: "We will talk to them about what opportunities exist to work more closely together and further IAG's ambitions as the leading global airline group."

IAG was formed from the merger of British Airways and Iberia in 2011. It has around 430 aircraft and employs more than 60,000 people.

A restructuring programme at the previously loss-making Iberia has seen 2,500 staff leave the airline under a voluntary redundancy programme.

The acquisition of the 9.99% stake by Qatar Airlines comes as IAG attempts to seal a £1 billion deal to buy the Irish carrier Aer Lingus.

IAG said it plans to operate Aer Lingus as a separate business with its own brand, management and operations.

Shares in IAG rose by more than 2% following the purchase by Qatar Airways in a move worth about £1.1 billion.

Its chief executive Akbar Al Baker said: "IAG represents an excellent opportunity to further develop our westwards strategy.

"Having joined the Oneworld alliance it makes sense for us to work more closely together in the near term, and we look forward to forging a long-term relationship."