Hong Kong, March 8 -- The resignation of China Southern Airlines from SkyTeam and the questioning of the benefits of oneworld membership by Qatar Airways Group CEO, Akbar al Baker, have reignited debate about the value of airline alliances.

China Southern, 2.76% owned by oneworld's American Airlines (AA), has close ties with oneworld's Qantas Airways. It also has long been tipped it was heading to the oneworld fold, but oneworld CEO, Rob Gurney, told Orient Aviation last month there was no basis for the rumour. "We are not in dialogue with China Southern about oneworld. We have Cathay Pacific, which is a terrific carrier," he said.

In the meantime, Al Baker, whose airline is a oneworld member, has used the alliance as a platform to voice...