By Siyi Liu and Florence Tan

SINGAPORE, July 8 (Reuters) - S&P Global Platts said on Tuesday it was proposing to change the pricing mechanism for United Arab Emirates' Murban crude in the Dubai oil benchmark from 2026 to better reflect market dynamics.

The price-reporting agency said in a document on its website that it was proposing the Abu Dhabi grade could be priced above, below or at parity with Dubai and other medium-sour grades in the basket.

Currently, a premium is applied to light-sour Murban to reflect its higher quality versus other medium-sour grades - Dubai, Oman, Upper Zakum and al-Shaheen - that can be delivered during the Platts Market on Close process that sets the Dubai benchmark price.

However, rising supplies of Murban crude have recently driven down the price of the grade, which in turn has weighed on the Dubai benchmark that prices more than 14 million barrels per day of Middle East oil to Asia.

Platts also said it planned to change the calculation in pricing Murban's quality difference with other grades in the Dubai basket.

Pending feedback from the industry, the changes will take effect from January 2, 2026, Platts said.

"The role of Murban in the Dubai basket has evolved in recent years in light of shifting market dynamics," Platts said.

"These include OPEC+ production cuts restraining the availability of medium sour grades and increased supplies of lighter, sweeter crudes at the same time, which have more frequently led to a narrowing or reversal of sweet/sour values."

Murban accounts for two-thirds of Abu Dhabi National Oil Co's ADNOC.UL production.

Upgrades at regional and global refineries have also increased demand for heavier and more sour crudes, Platts said.

"These market shifts have significantly increased the regularity with which Murban is declared into Dubai convergences and Murban has played a greater role in defining the benchmark," it added.

Under the proposed methodology, Platts would assess the daily Murban quality adjustment based on the net price differences between Platts assessments for Murban and Oman for cargoes loading two months ahead over five business days prior to the day of publication.

"This is great news for Dubai," a Singapore-based trader said, adding that the changes would prevent Murban from limiting gains for the Middle East benchmark.

(Reporting by Siyi Liu and Florence TanEditing by Mark Potter)

((siyi.liu@thomsonreuters.com))