The exit of the United Arab Emirates is the most significant in a series of departures from the oil cartel in recent years.

The decision by the United Arab Emirates to leave the OPEC oil cartel has shaken up the 65-year-old alliance that produces some 40% of the world’s crude oil and exerts major influence over the price of energy around the globe.

In announcing its country’s departure, the UAE ’s energy ministry thanked the other members of OPEC for “five decades of co-operation”. But its emollient words belie the fact that tensions in OPEC have been brewing for years.

The UAE wants to ramp up production without constraints from OPEC, which could prove bearish for prices at some point.

The group of oil-producing countries supplied more than 25 percent of the world’s oil before the war in Iran. Its members have influenced energy markets through the years.

UAE officials said the decision to depart the OPEC oil cartel comes after an "extensive review" of the country's oil production policy.

Brent crude and WTI prices were rising Wednesday as investors assess developments in the Iran war and OPEC.

Claudio Galimberti, chief economist of Rystad Energy, says Saudi Arabia will have to pull a lot of weight following the UAE's announcement that it will leave OPEC. He also says that both the U.S. and Iran are preparing for a protracted conflict,