An OPEC deal to cut oil output at a meeting this month is looking increasingly unlikely, with failure warranting prices in the low-$40s, according to Goldman Sachs Group Inc.

“The lack of progress on implementing production quotas and the growing discord between OPEC producers suggests a declining probability of reaching a deal on November 30,” Goldman analysts including Damien Courvalin wrote in a note dated Oct. 31. Obstacles to a supply agreement remain formidable, Greg Sharenow, .. Pimco portfolio manager, said in an e-mailed note on Tuesday.

The Organisation of Petroleum Exporting Countries is due to meet in Vienna to implement the first supply cuts in eight years and get other producers from outside of the group to join, notably Russia. Brent crude extended losses below $50 a barrel on Monday after weekend talks failed to yield concrete details on an accord to reduce the global crude surplus and stabilize prices.

“The lack of an agreement so far has pushed oil prices sharply lower, with weakening oil fundamentals warranting oil prices in the low $40s a barrel in our view if OPEC is unable to deliver a convincing agreement,” the Goldman analysts wrote.

Even if the fear of slumping oil prices prompts the group to hammer out an accord, the probability of the deal successfully reducing inventories is low, the bank said. Rising October OPEC production and a faster ramp up of new non-OPEC projects have reduced the odds that an agreement translates into a decent draw in inventories during the first half of 2017, it said, estimating average OPEC output at about 34.2 million barrels a day last month.