PFC, which has correctly called some of OPEC’s policy moves in the past, said the volatile backdrop of Middle Eastern unrest meant the June 8 meeting was taking place “in arguably the most contentious political setting in more than a decade.”

That complicates the task of reviewing output policy that has officially been in place since December 2008, although the group has since then informally leaked out extra barrels.

“Certainly, should prices remain near the $115 a barrel for Brent and $100 a barrel for WTI (US crude futures), there would seem to be little impetus for OPEC to take concerted action,” the Washington-based consultancy said in a note.

“For the time being, Saudi Arabia will likely continue to press for relatively high prices, but not at levels that can be seen as threatening to the global economy,” PFC said.

PFC cited Saudi Arabia’s huge bill to pay domestic subsidies to stabilize its population and a cooling of its ties with the US, where gasoline prices of around $4 a gallon in some states piled up political pressure for lower oil prices.

Whatever OPEC as a whole decides at its Vienna talks, most analysts expect Saudi Arabia, holder of the bulk of the world’s spare capacity that can be quickly added to the market, will increase output if it sees a need.

PFC Energy’s balances suggest OPEC output needs to rise by around 500,000 barrels per day above current levels to keep inventories at current levels.

It said an output increase around that level would likely be acceptable to those seeing the need for increased output, but also said current conditions were unlikely to allow for hammering out substantial policy changes.