China's Shanghai Airlines is to leave Star Alliance following the decision of its merger partner, China Eastern Airlines, to join rival SkyTeam.
China Eastern opted for SkyTeam in April and, at the time, the consequences of the decision on Shanghai Airlines were unclear.
Shanghai Airlines joined Star alongside Air China in 2007, the alliance's first members in the country.
But Star Alliance says that Shanghai Airlines has agreed "to terminate its membership" by 31 October.
Shanghai Airlines will continue to offer the associated alliance benefits until then.
Star says the airline's decision results from the merger with China Eastern, although Shanghai Airlines has not confirmed that it will join SkyTeam.