The period of delivery starts from the date from when the contract is awarded, the tender document said. The tender closes on Aug. 7, with offers to remain valid until Aug. 18.

PSO typically seeks fuel oil cargoes through spot tenders. It last bought 325,000 tonnes of HSFO and 165,000 tonnes of low sulphur fuel oil (LSFO) for delivery over July to September via a spot tender.

Fuel oil is used for power generation in Pakistan and demand usually peaks during the summer.

The country's total fuel oil imports in June stood above 500,000 tonnes for a third straight month, six percent lower than the previous month, data from the Oil Companies Advisory Committee (OCAC) showed.

This requirement comes at a time when the fuel oil market has been hit by uncertain demand and rising supplies.

"Two million tonnes is a huge volume, it could provide some support (to the fuel oil market)," a trader said.

 Singapore onshore fuel oil stocks for the week ended July 4 rose to 23.72 million barrels, its highest in more than two years, according to data released by state trade agency International Enterprise (IE).