Qatar Airways Chief Executive Officer Akbar Al Baker renewed his threat to abandon the Oneworld global alliance, citing a letter he said Australian partner Qantas Airways Ltd. had sent to staff attacking his carrier's expansion there.

Al Baker's comments on Tuesday mark a further deterioration in relations with Qantas, which has a joint venture with Qatar Air's Dubai-based rival Emirates. The CEO reiterated remarks from October saying he could abandon Oneworld if other members fail to act "in the spirit" of the partnership.

"I don't see any point in us continuing to stay a part of Oneworld when other partners see us as a threat," Al Baker said at an International Air Transport Association conference in Madrid. "We have put the chips on the table." He added that Qatar Air's expansion on routes to Australia had been at the invitation of the country's government.

The emergence of the rift has coincided with Qatar's battle against the impact of a blockade of its borders that's being led by Saudi Arabia and also includes the United Arab Emirates, where Dubai is located. While the state-owned airline's flight-paths and routes have been restricted, it's succeeding despite the "illegal" measures, Al Baker said.

Of the major Oneworld partners, Qatar Airways holds stakes in British Airways-owner IAG SA, the biggest South American carrier Latam Airlines Group SA, and Hong Kong-based Cathay Pacific. Those holdings mean that "Qatar doesn't need to be in an alliance," Al Baker said.