SCG Chemicals Files for $5.5 Billion Thai Petrochemicals Venture

SCG Chemicals filed to combine its Thai olefins and polyolefins businesses with those of PTT Global Chemical in a proposed venture valued at $5.5 billion, as Siam Cement Group CEO Thammasak Sethaudom argued that manufacturers need regional scale to compete with Chinese supply.

The combined businesses were valued at 187 billion Thai baht ($5.5 billion). SCG Chemicals would hold 44% of the proposed venture. PTT Global Chemical is Thailand’s largest petrochemical company, and shareholders are scheduled to vote on the combination Dec. 3.

Olefins and polyolefins are part of the petrochemicals industry, which makes materials used in plastics and other industrial products. The proposed combination comes as Sethaudom says Chinese products are reaching markets across Southeast Asia and putting pressure on regional producers.

At a summit in Ho Chi Minh City on Nov. 3, Sethaudom described Chinese overcapacity as a condition SCG must adapt to. “To SCG, this is the fact of life, and we have to adjust,” he said. He argued that production aimed only at Vietnam may not provide enough scale, and that manufacturers need to serve the wider ASEAN region.

Sethaudom also said SCG is building a ceramics plant in Vietnam that is much larger than its previous facility. He described the project as part of a shift from smaller factories toward larger production sites.

China’s polypropylene exports rose to 3.1 million metric tons in 2025 from 1.3 million metric tons in 2022. Polypropylene is a widely used plastic. The export figures provide a measure of the Chinese supply pressure Sethaudom described for manufacturers elsewhere in Southeast Asia.

Shareholders are scheduled to vote on the proposed combination Dec. 3.