Brent crude futures settled down 31 cents at $79.39 a barrel and U.S. WTI crude futures dropped 33 cents to $73.89 a barrel

Oil prices settled lower on Thursday after Angola said it would exit the Organization of the Petroleum Exporting Countries (OPEC), raising questions about the producer group’s attempts to support prices by limiting global supplies.

Brent crude futures settled down 31 cents at $79.39 a barrel. U.S. West Texas Intermediate (WTI) crude futures dropped 33 cents to $73.89 a barrel.

Earlier in the session, both benchmarks were lower by more than $1 after Angola said it was planning to leave the group.

Angolan oil minister Diamantino Azevedo said the country’s membership in OPEC was not serving its interests. The producer group in recent months has been rallying support to deepen output cuts and support oil prices.

It seems like Organization of the Petroleum Exporting Countries is losing the battle to keep prices higher, said Matt Smith of shipping tracking company Kpler, noting that non-OPEC producers such as the U.S. have stepped up to fill the supply gap.

Angola produces nearly 1.1 million bpd, compared with 28 million bpd for the whole group.

The country’s exit raises questions about the cohesion and direction of Organization of the Petroleum Exporting Countries, even though it is one of the smallest producers and its departure may have a limited impact on global supplies, Smith said.

At a meeting in November, Angola had protested a decision by OPEC to cut its production quota for 2024 to help strengthen oil prices.

Separately, the U.S. EIA said U.S. crude output increased to a record 13.3 million bpd last week, up from the earlier all-time high of 13.2 million bpd.

The U.S. is poised to raise production in the Permian Basin and across the country, said Tim Snyder, economist at Matador Economics in Dallas.

We have mitigated price risk here in the U.S. and really put the Russians and the Saudis back on their heels, he added.