Kuwait has decided to permanently shut its heavy oil cracking unit at its Shuaiba refinery which has been shut since a fire at the unit in August, a spokesman for the state refiner said on Wednesday.

The closure of the unit has reduced the gasoil sales of Kuwait National Petroleum Company (KNPC) by around 50,000 barrels per day, KNPC spokesman Khalid Al-Asousi said.

That would mean more crude sales by parent company Kuwait Petroleum Corp (KPC), he said.

"The H-Oil start-up will not be economical as it will take time and Shuaiba refinery will be closed by April 2017," Al-Asousi said.

Shuaiba is Kuwait's smallest refinery. It has a capacity of 200,000 bpd, but has been running at less than full capacity since the fire.