Government may further extend the anti-dumping duty levied on imports of a chemical, used in plastic and other industry, from six countries, including China and Korea, to protect domestic players from cheap shipments.In the final findings of the sunset review, Directorate General of Anti-dumping and Allied Duties (DGAD), has suggested the duty of up to Rs 379 per tonne on the imports of 'Poly Vinyl Chloride (PVC) Paste/ Emulsion Resin'.