Thailand's top industrial conglomerate - Siam Cement, in a joint venture with Vietnamese companies to build a US$3.5-4 bln petrochemical plant in southern Vietnam. Siam Cement subsidiaries would own 71% stake in the plant, while Vietnam Oil, Gas Group (Petrovietnam) and Vietnam National Chemical Corporation will hold the balance. The investment in acquistion of stake through its Vina SCG Chemicals and its 44.7% owned Thai Plastic and Chemicals (Thailand's largets PVC maker), is subject to approval by the Vietnamese government. The plant is to be located in Long Son in the province of Ba Ria-Vung Tau, adjacent to Vietnam's third refinery. The plant is scheduled to come onstream in 2011. A second phase of the plant will commence operations in 2013, resulting in 1.65 mln tpa of olefins, 1.45 mln tpa of polyolefins and 280,000 tpa of Chlor-Alkali.