Iran has told OPEC it pumped 3.63 million barrels of oil per day (bpd) in August, up 10,000 bpd from July, an OPEC source said, marking a slowdown in the rapid growth that followed the lifting of Western sanctions in January.

“Iran wants a stable market and therefore any measure that helps the stabilisation of the oil market is supported by Iran,” Mr Zanganeh said. “We support oil prices between $50 and $60 per barrel.”

"We have held conversations on strengthening our position in oil markets," Iran's Foreign Minister Mohammad Javad Zarif said through an interpreter after a meeting with Ecuador's President Rafael Correa. Zarif added that the two countries have agreed to continue talks within the framework of OPEC, without providing further details. Ecuador Foreign Minister Guillaume Long said they discussed establishing a common position with regards to strengthening oil prices.

Iran sent a letter to members of the Organization of the Petroleum Exporting Countries saying it would attend the group’s informal talks in Algeria in September, OPEC delegates told The Wall Street Journal. An Iranian oil-ministry press official couldn’t confirm the letter had been sent late Tuesday.

Prices have struggled to go much higher than $50 a barrel. After the longest run of gains since March, Brent crude, the international benchmark, traded 0.9 percent higher at $51.17 at 7:13 a.m. in London on Friday.

The world's fifth-largest crude importer has continued to buy more crude oil from Iran since sanctions were lifted in January. Shipments of Iranian crude more than doubled to 7.22 million tonnes, or 248,616 bpd, in the January-July period of 2016 from a year earlier, according to its customs office data.

Indonesia's Pertamina has signed a deal with Petrochemical Commercial Company (PCC) of Iran for the import of refined petroleum and petrochemical products.

Turkey wants to buy more natural gas from Iran and has discussed pricing issues, Foreign Minister Mevlut Cavusoglu said on Friday, adding that Ankara and Tehran should resolve a dispute on gas prices without arbitration.

Saudi Arabia, the world’s largest crude exporter, told OPEC that it boosted oil output to a record 10.67 million barrels a day in July, two people with knowledge of the data said. Iran’s output is up to 3.85 million barrels a day, Fars news agency reported, citing Oil Minister Bijan Namdar Zanganeh.

The government hopes foreign companies will invest as much as $50 billion a year in Iran’s oil industry. Major European oil companies such as Italy’s Eni SpA and France’s Total SA have expressed an interest in developing Iran’s oil and gas fields.