The units were shut June 30 because of a technical problem.
Petrochem's polymers plant at Jubail has a 1.16 million mt/year ethylene unit, a 1.1 million mt/year polyethylene unit, a 430,000 mt/year propylene unit, a 400,000 mt/year of polypropylene unit, a 200,000 mt/year polystyrene unit and a 100,000 mt/year 1-hexene unit.
The plant had begun commercial operations at the end of September 2012.
Saudi Polymers Company is a joint venture between Petrochem (65%) and Arabian Chevron Phillips Petrochemical Company (35%).