Platts survey of OPEC and oil industry officials and analysts showed that May production marks a rise from April's output level of 31.71 million b/d and is the highest level since October 2008 when OPEC volumes averaged 32.26 million b/d.
"The number that really matters is the jump from January to May this year, which shows that OPEC output rose from 30.87 million b/d in January to 31.75 million b/d last month," said John Kingston, Platts global director of news.
"This has occurred even as Iranian supplies were being squeezed by a drop in the number of customers willing to take its oil. We can now assume OPEC members at least will discuss at their upcoming meeting a possible paring of production. This scenario was almost impossible to fathom just a few months ago, as OPEC continues to surprise the world with its ability to put oil on to the market,