SINGAPORE - Malaysia's Pengerang Refining and Petrochemical (PRefChem), a joint venture between Petronas and Saudi Aramco, is exporting a gasoline cargo this week despite its new refinery not being fully operational, an industry source said on Wednesday.

A medium-range vessel-size cargo, which typically is about 35,000 tonnes, was sold to Emirates National Oil Company (ENOC) of United Arab Emirates (UAE) at premiums of about $5 a barrel to Singapore quotes on a free-on-board basis, they added.

This could not be independently confirmed as buyers and sellers do not comment on their deals.

The cargo, which is likely to be the refinery's first gasoline export, is scheduled for loading from Pengerang within a few days, the sources said.

Petronas said last week that its 300,000 barrels per day refinery in southern Malaysia will start commercial operations as planned by the end of the year.

It added that the refinery's atmospheric residue desulphurisation (ARDS) unit, which was hit by a fire in April, will begin operation by mid-2020.

The ARDS unit removes sulphur from fuel oil, which is then used as a raw material to produce gasoline in a residue fluid catalytic cracker (RFCC).

(Reporting by Seng Li Peng and Koustav Samanta, editing by Louise Heavens) ((lipeng.seng@thomsonreuters.com; +65 6870 3086; Reuters Messaging: lipeng.seng.thomsonreuters.com@reuters.net))