This is the highest premium it has paid for the open-specification grade since July, Reuters data showed.

Asia's top naphtha importer bought around 100,000 tonnes of the open-specification grade for second-half March arrival at Mailiao.

It typically buys the grade for every half-month delivery to feed its three naphtha crackers, but it had skipped buying the open-specification grade for first-half March.

(Reporting by Seng Li Peng; Editing by Subhranshu Sahu)