Qatar Airways has threatened to split the Oneworld alliance which it joined in 2013 because of a dispute with American Airlines. For the UK, this puts pressure on the International Airlines Group (IAG) which is 10% owned by Qatar Airways.

The Oneworld alliance brings together 15 of the world's leading airlines and around 30 affiliated carriers. Together, these airlines operate more than 14,000 daily flights to some 1,000 destinations across the globe, according to its website.

During the recent launch of the company's new carrier services between the American west coast and Doha, Akbar al-Baker, the chief executive at Qatar Airways, publicly condemned attempts by American Airlines, a founder member of Oneworld, to block its expansion into the US.

"We don't get bullied by anybody. If American [Airlines] does not want to work fairly with us, we will consult the others and we could form our own mini-alliance if we wanted to," al-Baker said, adding that he would not bear a situation where "conditions are no longer conducive to a fair business relationship and mutual respect".

This is the first time the Doha-based company has threatened to split the alliance over its dispute with American Airlines, which other Gulf airlines such as Emirates and Etihad too have accused of protectionism.

The sharp remarks follow increasing tensions between the Gulf carriers and US airlines. American carriers have alleged that Gulf airlines are subsidised by Middle East governments and want Washington to prevent their expansion.

For IAG, the owner of British Airways, which recently signed a deal with Latam Airlines to expand into South America, its future international alliances could be affected if Qatar Airways decides to split, which has long been regarded as the most successful of the three global aviation alliances.

An IAG spokesman, while refusing to comment on al-Baker's remarks, said its chief executive, Willie Walsh, had for long argued for "open and fair competition". This indicates that IAG would also split from the Oneworld alliance if its shareholder Qatar chooses to quit, according to The Times.