PSO is looking to buy a 35,000 tonne 87-octane parcel for prompt June 23-25 arrival at Karachi in a tender closing June 16.

Offers are to stay valid until June 20.

Attock Refinery Ltd (ARL) shut a platformer at its 45,000 barrel per day (bpd) plant for maintenance last week, which would last about a month.

This came shortly after Pakistan Refinery Ltd (PRL) restarted a 47,100 bpd refinery following a three-week maintenance period, which started in May.

The almost back-to-back shutdown has disrupted supplies.

"PRL has restarted, but ARL has now shut its platformer, and the shutdown came earlier than planned," said a trader, who did not specify the original maintenance dates.

PSO early in the week bought 50,000 tonnes of gasoline for June 14-16 arrival from Vitol at premiums of $89.00 a tonne to Middle East naphtha quotes on a cost-and-freight (C&F) basis.

Copyright Reuters, 2011