SINGAPORE - A supertanker carrying the first crude oil cargo to a refinery being jointly built by Malaysia's Petronas and oil giant Saudi Aramco has arrived at Pengerang, as the two companies enter the commissioning and testing phase at the plant.

Construction of the 300,000 barrels-per-day (bpd) refinery at the Pengerang Integrated complex is nearing completion, Petroliam Nasional Berhad (Petronas) said in a statement issued late on Monday.

The cargo of 2 million barrels of crude oil supplied by Petronas and Aramco will be used for the commissioning and testing activities which are scheduled to start in October, Petronas added.

"The arrival of the cargo signifies our readiness to move forward to start-up and commercial operations," said Colin Wong Hee Huing, chief executive of PRefChem which is an alliance of both companies.

He added that the refinery was on track to start up in the first quarter of 2019.

Once completed, the refinery will produce a range of refined oil products including gasoline and diesel which meet Euro 5 fuel specifications, Petronas said.

Additionally, the refinery will provide feedstock for the integrated petrochemicals complex.

Speaking earlier at the Asia Pacific Petroleum Conference, Ibrahim Al-Buainain, Aramco Trading Company's president and chief executive, said that the first crude oil cargo for the Malaysian project was discharging out of a very large crude carrier (VLCC).

The supertanker Navarin carrying 1 million barrels each of Saudi Arab Medium crude and Iraqi Basra Light crude arrived in Malaysia on Sept. 21 and is now moored off the Pengerang oil terminal, according to trade sources and shipping data on Thomson Reuters Eikon.

The $27 billion refining and petrochemical project located between the Malacca Strait and the South China Sea, is a conduit for Middle East oil and gas bound for China, Japan and South Korea.

"This is part of our downstream strategy," Buainain said. "Asia is a key market for us and most of the demand is from this region."

(Additional reporting by A. Ananthalakshmi in KUALA LUMPUR; editing by Richard Pullin and Kirsten Donovan) ((Jessica.Jaganathan@thomsonreuters.com; +65 6870 3822; Reuters Messaging: jessica.jaganathan.thomsonreuters.com@reuters.net; Twitter: https://twitter.com/j3ssi3))