Indonesia's state-owned Pertamina on Monday signed a memorandum of understanding to conduct preliminary studies on two Iranian oilfields, a step closer to the company's first investment in the Middle Eastern country's upstream sector.

Under the agreement, Pertamina has six months to look into Iran's Ab-Teymor and Mansouri oilfields, which are located onshore and contain an estimated total reserves of more than five billion barrels.

"Iran is one of Pertamina's priorities. We're serious about investing in Iran's upstream oil and gas, which will help Iran to increase its oil production," said Pertamina CEO Dwi Soetjipto in a statement.

Iran has been able to raise its crude oil output to around 3.6 million barrels per day (bpd) since international sanctions were lifted in January, and the country, the world's sixth-largest oil producer, may reach its pre-sanctions production levels in coming months.

Still, Tehran is looking to boost investment in oil and gas infrastructure and field development that has stagnated over the last few years.

Pertamina also said it would import its first shipment of liquid petroleum gas (LPG) from Iran in September.

Pertamina in May agreed to purchase 600,000 tonnes of LPG from state-owned marketer National Iranian Oil Co (NIOC). – Reuters