TOP expects bright prospects from business expansion into these countries.
According to The Bangkok Post, the Thai firm has facilities such as warehouses in the northern and southern regions of Vietnam.
Wirat Uanarumit, president and chief executive of TOP, said high rates of economic growth and large numbers of young people among the populations of the three countries mean these nations offer the best potential for investments in Asia.
TOP is expanding its business abroad to meet the growing demand for energy and petrochemical products.