Shares in PTT Global Chemical Pcl fell on concerns about expenses that may arise due to an oil leak from its pipeline in the sea off Thailand's eastern province of Rayong on Saturday, traders said.
Environmentalists are calling for compensation and legal action against the company following the oil spill, according to media reports.
PTT Global shares fell 2 percent to 72.5 baht versus a 1 percent loss in the energy subindex. The broader SET index was down 1.3 percent.
1036 (0336 GMT) (Reporting by Viparat Jantraprap; Editing by Sunil Nair)