Saudi Kayan Petrochemical Company on Tuesday brought forward by one month, maintenance plans for some units at its complex in Jubail.
The Saudi Basic Industries Corpoartion (Sabic) affiliate will start the shutdown on March 1 rather than March 30, it said in a bourse filing.
The shutdown had been postponed from October 31, 2015.
The company said its ethylene glycol/ethylene oxide plant would be shut for maintenance and repairs for 48 days.
That would result in halting production of polycarbonate, ethoxylates and amines for 53 days.
Kayan said the financial impact of the shutdown would amount to around 96 million riyals ($25.6 million), which will be reflected in its first- and second-quarter results.
When it first announced the maintenance plan in February 2015, it had warned the shutdown would result in a loss of 340 million riyals and that it would halt production for 60 to 75 days.