Saudi Kayan Petrochemical Co said it had extended the maintenance work on the olefins plant at its petrochemicals complex in Jubail after a technical fault was discovered.

In a bourse filing, the company said repairing the fault was expected to be completed within 10 days.

The impact of the fault, along with another one that had been found and repaired in another unit, had been calculated to be around SR310 million ($83 million) at current prices, which will be reflected in first-quarter results, it said.

This is significantly higher than the SR62 million which the company forecast the original maintenance work would cost when it announced last month the olefins plant would be shut from February 1 for almost five weeks.

Kayan, an affiliate of Saudi Basic Industries Corp (Sabic), said at the time the impact would be offset by Kayan's inventories and other Sabic units.

"Maintenance work had been completed according to schedule and when work started to restore production to the normal level, a technical fault was discovered in the olefins plant which necessitated extending the maintenance period," the company said in the statement.

It said the repairs would entail temporary stoppage of the high density polyethylene and the low density polyethylene plants, and reduced production at the ethylene glycol and polypropylene plants which are being supplied by the olefins plant. - Reuters