Prayuth Chan-ocha late on Monday said more than 18 months of mandatory quarantine would end https://www.reuters.com/world/asia-pacific/thailand-end-quarantine-some-vaccinated-visitors-nov-pm-2021-10-11 next month for vaccinated arrivals from countries considered "low risk", including the United States, Britain and China.
The stock exchange's tourism and leisure index jumped as much as 4.42% when markets opened on Tuesday, compared to a benchmark increase of 0.82%.
Gains were driven by a 4% rise in Airports of Thailand Pcl, Asia Aviation Pcl and Bangkok Airlines Pcl, which rose 5.59% and 3.42%, respectively.
Hotelier, Erawan Group Pcl increased nearly 7% and rival Asset World Corp climbed over 4%.
Thailand's strict entry requirements had kept COVID-19 infection numbers low until this year, but at a huge loss to jobs and revenues in its vital tourism sector.
Since July, it has operated pilot projects on Samui and Phuket islands allowing for vaccinated visitors and this month reduced quarantine periods elsewhere.
But arrivals have plummeted to a fraction of the nearly 40 million visitors in 2019, with tourism losing $50 billion in annual revenue, an 82% plunge.
Despite its stringent measures to keep the virus out, Thailand has recorded 1.7 million infections and 17,835 COVID-19 deaths, with 98% of its caseload since April.
A third of its 72 million residents are vaccinated.
The announcement follows Britain's removal of Thailand from its travel red list https://www.reuters.com/world/uk/uk-eases-travel-rules-countries-including-india-2021-10-07 last week.
Analysts said that although foreign arrivals may not increase quickly, domestic activity would be boosted.
"A reopening would mean that full mobility is restored ... we are much optimistic on the domestic travel and consumption," said Maria Lapiz, head of institutional research at Maybank Kim Eng.
(Reporting by Chayut Setboonsarng; Editing by Martin Petty)