Nakhonchai Air Co is planning to launch domestic bus services in Cambodia and Myanmar, which could start as early as next year.
The firm's managing director Krueawal Wongrakmit said the organisation is in talks with officials from Cambodia and Myanmar and is studying regulations on public transport in the two countries.
If everything goes as planned, the company could start offering services next year or in 2015, she added.
Nakhonchai runs first class air-conditioned bus lines from Bangkok to the northern, northeastern and eastern regions, and several direct routes linking the three regions, with a fleet of 300 buses.
The decision to expand abroad would make it the first Thai firm to operate bus lines outside of Thailand.
The company does not plan to run inter-country bus services, because Transport Co, a state enterprise under the Transport Ministry, already operates air-conditioned buses from Bangkok to Laos and Cambodia.
"Nakhonchai is not interested in bus services from Thailand to neighbouring countries, because the Transport Co runs those already. We are opting to run a domestic service for our neighbours,'' Mrs Krueawal said.