SK Global Chemical Co. Ltd., a South Korean chemicals maker, said Thursday that it will invest 370 billion won (US$345 million) to build a polyethylene plant in the southeastern part of the country. The plant will be built in Ulsan, some 414 kilometers southeast of Seoul, and have an annual production capacity of 230,000 tons of \"nexlene,\" an advanced type of polyethylene invented by the company last year, SK Global Chemical said.