Abu Dhabi allowed trading of a futures contract linked to its flagship grade of crude for the first time on Monday in a debut that could test OPEC’s grip on oil prices. Prices for Murban futures rose 0.6% to $63.90 a barrel on Intercontinental Exchange Inc.’s new ICE Futures Abu Dhabi marketplace. Trading was brisk: More than 6,300 lots, equating to over 6.3 million barrels of crude, changed hands by 5 p.m. local time, or 9 a.m. ET.

Futures for Brent crude, the benchmark in international energy markets, edged up 0.6% to $64.98 a barrel after engineers freed the container ship that had blocked the Suez Canal, a thoroughfare for oil and gas. West Texas Intermediate, the main grade of U.S. crude, rose 1% to $61.56 a barrel. Abu Dhabi plans to relinquish control over prices of Murban to investors and traders, a major step in efforts to fortify its position in the international oil market. The goal is to make Murban more attractive to refiners in Asia, where oil producers are battling for customers as Western governments seek to phase out fossil fuels.

By allowing crude to trade more freely, the emirate could ultimately undermine the sway of the Organization of the Petroleum Exporting Countries over prices. The changes that Abu Dhabi is making will erode the influence of cartel leader Saudi Arabia over time, said Philip Verleger, an energy economist and president of PKVerleger LLC.

Crude-oil prices since 2019Source: Argus Media .a barrelMurbanWest TexasIntermediate2020’21-50-40-30-20-10010203040506070$80

“Oil will flow more freely around the world where it is needed, and that will make it more difficult for OPEC to maintain control on prices,” Mr. Verleger said.

Murban is a staple for Asian refiners, prized for its relatively low viscosity and sulfur content. State-owned Abu Dhabi National Oil Co. has vied for buyers with American companies alongside Mideast exporters since the shale boom unleashed oil in the U.S.

Traditionally, Adnoc set export prices for Murban retroactively. During the crisis in energy markets last March, it began setting prices one month ahead at a differential to an assessment of Dubai crude prices by S&P Global Platts. For deliveries from June, Adnoc will set prices two months in advance, using freely-traded Murban futures as a reference.

Adnoc also is ending the practice of forbidding resales. Like Saudi Arabian Oil Co. , or Aramco, Adnoc has historically limited trading to maintain control over its crude.

“That’s pretty revolutionary,” said Mike Muller, head of oil trading at Vitol Group, the world’s biggest independent oil trader and a shareholder in ICE Futures Abu Dhabi. Lifting restrictions will foster a more lively spot market for oil in Asia, where refiners buy most crude under long-term deals, he said.