Supply from all 12 members of the Organization of the Petroleum Exporting Countries is expected to average 30.07 million barrels per day (bpd) this month, up from a revised 29.81 million bpd in June, the survey of oil companies, OPEC officials and analysts found.

Output this month is the highest since October 2008, according to Reuters estimates.

June’s total was revised up to reflect higher production in Saudi Arabia and Iraq than initially thought.

OPEC supply is higher than before the war in Libya halted exports from what used to be Africa’s third-largest producer.

Analysts said the extra barrels should help lower prices, which are trading above $118 a barrel.

“This should close the gap between OPEC output and the call on OPEC, which was visible in the last couple of months due to the Libyan supply shortfall,” said Carsten Fritsch, analyst at Commerzbank.

“Higher supplies from Saudi Arabia and other OPEC members should help to increase output to levels which lower prices.”

Saudi Arabia and fellow Gulf OPEC countries also raised their output in June after the group’s meeting on June 8, when seven members of the 12-nation OPEC blocked a proposal to increase output targets.

The International Energy Agency last month ordered the release of oil from emergency stocks for only the third time in its 37-year history after OPEC failed to agree to a formal output increase.

The IEA, which advises 28 industrialized countries, decided last week against making a second release, saying extra supply from OPEC and the IEA reserves had made the market outlook more comfortable.

Commerzbank expects Brent to fall toward $100 by the end of the year, although the risk of supply disruption from a Gulf of Mexico storm prevented a price fall for now, Fritsch said.

The biggest change this month is in Angola, where supply has rebounded because of a reduced impact from oilfield maintenance.

BP said on July 1 it had restarted the 170,000-190,000 bpd Plutonio oilfield in Angola after a more than two-month partial outage for maintenance work.

Even so, export schedules suggest the rise will be short-lived and output will fall in August.

Saudi Arabia has raised its supplies, including both exports and use in domestic power plants, by a further 170,000 bpd this month, the survey found.

Petroleum and Mineral Resources Minister Ali Al-Naimi said after the June OPEC meeting that Riyadh was ready to supply the market with whatever oil it needed, despite the lack of an OPEC agreement. 

OPEC still has a way to go to close the gap completely between its production and forecast demand. OPEC expects demand for its oil to average 30.85 million bpd in the second half of 2011.

Output has fallen in several OPEC members this month, including No. 2 producer Iran.

Iranian exports slipped from a relatively high level in June, shipping sources said, and Iran said it had temporarily cut shipments to India citing Indian technical problems. The two countries are in the midst of an oil sales payments dispute.

Supply in Nigeria, Africa’s top producer, fell slightly for a second month.

Libya’s production posted a further decline to a nominal 50,000 bpd. Output was running at almost 1.6 million bpd in January before the conflict.

OPEC has not officially changed its output policy since cutting output by a record 4.2 million bpd in December 2008 to 24.84 million bpd for 11 members, all except Iraq, to combat falling prices and a collapse in demand.

Since their June meeting, OPEC officials have acknowledged the target is no longer valid as actual supply is so much higher.

OPEC does not provide timely official production figures so the oil industry relies on outside supply estimates from news agencies, consulting firms and government organizations.