Oil prices fell today, surrendering earlier gains as investors weighed up the effectiveness of a potential cut in supply from OPEC and possibly other exporters in the face of rapidly rising global output. 

Brent crude futures were down $1.04 at $65.72 a barrel this afternoon, having retreated from a session high of $67.64. WTI crude futures fell $1.03 to $55.43 a barrel. 

The Organization of the Petroleum Exporting Countries, led by Saudi Arabia, is pushing for the group and its partners to reduce output by 1 million to 1.4 million barrels per day to prevent a build-up of unused fuel. 

Russian Energy Minister Alexander Novak said today that Russia, which is not an OPEC member, planned to sign a partnership agreement with the group, and that details would be discussed at OPEC's December 6 meeting in Vienna. 

Brent is almost 25% below early October's 2018 peak of $86.74, as evidence of slowing demand has materialised and output from the United States, Russia and Saudi Arabia hit historic highs. 

A US decision to grant waivers to some of Iran's oil customers, who faced the prospect of a drop-off in supply from sanctions that came into force in early November, has also helped soothe concern about availability of crude. 

A trade dispute between the US and China is one reason investors are a lot warier about the outlook for oil demand growth next year.