"LG Chem is considering to carry out regular maintenance at its Daesan NCC, which has an ethylene capacity of 1.3 million tonnes per year, sometime during the second half of the year," he said.

He added that the schedule had not been fixed for the maintenance which usually takes about four weeks to complete.

LG Chem declined to comment.

The company's new 800,000-tpy cracker in Yeosu which started operations in June, has reached full operating rate, the source said.

LG Chem, operates three naphtha crackers with a total ethylene capacity of 3.3 million tpy.

(Reporting by Heekyong Kang; Writing by Florence Tan; editing by David Evans)