Willie Walsh, chief executive of International Airlines Group, is looking at a closer relationship with American Airlines through the acquisition of a minor stake. American has been looking for investment after it filed for protection against bankruptcy last year and is currently in talks with its banks about easing its debt burden.

IAG, the company formed after British Airways and Iberia merged, wants American Airlines to stay in the Oneworld airline alliance. This would ensure that British Airways would have continued access to a network of transatlantic routes.

However, Delta Airlines has also expressed an interest in investing in American. This would probably mean that American would move over to the Sky Team alliance. The fact that Delta is already the second largest carrier in the US might bring up issues with the competition regulators.

Another option on the table is for US Airways to take a stake in American. The carrier is the fifth biggest in the US and would not produce such a problem for the regulators. The result would also be better for British Airways because it would probably result in US Airways joining the Oneworld alliance.

Delta recently spent $100 million on acquiring a five per cent stake in Gol, the Brazilian airline. The investment was made so that Gol would not be tempted to defect to the Oneworld alliance.