Thai Airways International plans to raise frequencies on services from Bangkok to Dhaka and Jakarta, starting 1 July.
The Bangkok-Dhaka service will increase from seven to 11 times weekly, while the Bangkok-Jakarta service will be doubled to twice daily, says a spokeswoman for the Star Alliance carrier.
It will use Airbus A330 aircraft on the two additional services.
Innovata schedules show that Thai competes with carriers such as Bangkok Airways to Dhaka and Garuda Indonesia on services to Jakarta.
In addition, the carrier has cancelled plans to raise the Bangkok-Osaka Kansai service from 17 to 18 times weekly, starting 31 March. It did not, however, specify reasons for the change.
Thai will also reduce frequency on the Bangkok-Taipei Taoyuan route from 18 to 14 times weekly, adds the spokeswoman.