Thai Airways International will end its twice-daily Bangkok-Koh Samui service on 2 September.
The carrier stresses, however, that it will still be connected to Koh Samui via codeshares with Bangkok Airways.
Thai did not respond to FlightGlobal's query on whether the service termination is related to the planned retirement of its sole narrowbody, a Boeing 737-400 registered HS-TDG.
FlightGlobal schedules data shows that the 737 is only used on flights to Koh Samui, which has a 2,100m runway. While subsidiary Thai Smile could operate Airbus A320s into Koh Samui, this would require severe payload restrictions.
Besides the 737s, A319s and ATR 72s are the two other aircraft types predominantly used on services to Koh Samui.