Saudi Arabia’s Sadara Basic Services, fully owned by Sadara Chemical Co, said it would start on Wednesday planned maintenance of a mixed-feed cracker at its parent company’s petrochemical complex in Jubail.

The shutdown of the facility is expected to last six weeks, with the company’s three polyethylene trains also shut during the period as Sadara completes improvements to their reliability and scheduled maintenance, it said in a bourse statement on Tuesday.

An evaluation of the financial impact of the shutdowns will be released in the company’s first quarter 2017 financial statements, it said.

Sadara Chemical is a $20bn petrochemical joint venture between national oil giant Saudi Aramco and Dow Chemical.