The organisation's two fixed-term employees based in Bangkok, will finish by the end of the December.
Chief Executive Kevin Bowler says over the coming months, staff will continue to deliver activity and plan ahead to ensure continuity is achieved over the full financial year.
"With this decision we will consolidate our focus in South and South East Asia, with particular emphasis on generating value from the India market. We will continue to support Thai Airways but again, with greater focus on its connection into India."
Visitor arrivals from Thailand remain modest, having grown from 17,000 in 2006 to 24,000 in June 2016. Thailand's share of Asian visitors is also shrinking from 3.6% (2014) to 2.8% (2016).
Kevin says: "The limited investment we have been making in the market is making limited impact but stretching our resource and focus.
"We need to be sure that our investment is targeted toward the greatest opportunities available, and is delivering the best return possible which is the reason for this decision to close."