China Southern Airlines will not renew its contract with SkyTeam, one of the world’s three airline alliances, the company said Thursday.

The decision was made for “strategic purposes” and to conform to “new trends” worldwide in the airline industry, China Southern said in a statement posted on WeChat.

Skyteam was founded in 2000 by Aeroméxico, Air France, Delta Air Lines and Korean Air, and now features 20 member airlines. The world’s other two airline alliances are Oneworld and Star Alliance.

China Southern said it will strengthen its cooperation with American Airlines — a Oneworld member — which took a 2.76% stake in China Southern in 2017.

If China Southern were to join Oneworld — which has been rumored — it would be the first mainland Chinese airline in the group. Such a move could be bad news for Hong Kong’s Cathay.

“With China Southern eyeing membership in Oneworld, which already includes Cathay Pacific and Cathay Dragon, Hong Kong’s flagship carrier could in turn move to Star Alliance,” SCMP reported. “Remaining in Oneworld with China Southern would bring the two carriers’ home bases of Hong Kong and Guangzhou too close together, with destinations they serve overlapping and the airlines competing for the same pool of long-haul travellers.”