BANGKOK (Reuters) - PTT Global Chemical Pcl (>> PTT Global Chemical PCL), Thailand's largest petrochemical producer, on Tuesday announced a $4 billion (3 billion pounds) investment plan over the next five years in an industrial development on the eastern seaboard.

It includes a polyols joint venture between PTTGC, Sanyo Chemical Industries (>> Sanyo Chemical Industries Ltd) and Toyota Tsusho Corp (>> Toyota Tsusho Corp) in Thailand's eastern province of Rayong, it said.

The investment plan also includes a naphtha cracker plant at the existing PTTGC facility in Map Ta Phut which will put production capacity at 500,000 tons per year for ethylene and 250,000 tons per year for propylene.

PTTGC also signed an agreement with Japanese Kuraray Co (>> Kuraray Co Ltd) and Sumitomo Corp (>> Sumitomo Corp) to study the possibility of producing High-Heat Resistant Polyamide-9T and Hydrogenated Styenic Block Copolymer.

(Reporting by Panu Wongcha-um; Editing by Christian Schmollinger)