OPEC agreed on Friday on a modest increase in oil production from July after its leader Saudi Arabia persuaded arch-rival Iran to cooperate amid calls from major consumers to help reduce the price of crude and avoid a supply shortage.

Two OPEC sources said the group agreed that OPEC and its allies led by Russia should increase production by about 1 million barrels per day (bpd), or 1 percent of global supply.

The real increase will be smaller because several countries that recently underproduced oil will struggle to return to full quotas while other producers will not be allowed to fill the gap, OPEC sources have said.

Saudi Energy Minister Khalid al-Falih appears to have convinced his Iranian peer Bijan Zanganeh to support the increase just hours before Friday's OPEC meeting.

OPEC and its allies have since last year been participating in a pact to cut output by 1.8 million bpd. The measure has helped rebalance the market in the past 18 months and lifted oil to around $75 per barrel from as low as $27 in 2016.

But unexpected outages in Venezuela, Libya and Angola have effectively brought supply cuts to around 2.8 million bpd in recent months.

Brent oil prices were up 1.9 percent on Friday as the output boost had been largely priced in and was seen as modest.

"It will be enough for now but not enough for the fourth quarter to address a decline in Iranian and Venezuelan exports," said Gary Ross, head of global oil analytics at S&P Global.

"There isn’t a lot of spare capacity in the world. If we lose a million bpd of output from Venezuela and Iran in the fourth quarter, where will all these barrels come from? We are in for higher prices for longer," he said.

The OPEC meeting began around 1000 GMT and was continuing after two and a half hours.