Commodities trader Glencore has sold 1 million barrels of June-loading Murban crude to U.S. refiner Marathon Petroleum Corp. (MPC) in a rare deal, traders said on April 14, as more U.S. refiners seek replacements for Russian oil.

The deal also comes as the economics of moving Middle East crude to the U.S., the world’s No. 2 crude importer, have become attractive, they said.

An MPC spokesperson said the company does not typically discuss crude sourcing. Glencore did not respond to a request for comment.

Murban is a flagship grade produced in Abu Dhabi in the United Arab Emirates, and is typically consumed in Asia.

Up to 11 million barrels of Murban crude is estimated to have traded in the spot market over the past week after its spot premiums fell to the lowest in two months.

Murban, prized for its high middle distillates content and similar in quality to Russian Sokol and ESPO crude, is well sought after by refiners in Asia and the U.S. which are ramping up output for diesel and jet fuel.

Refining margins for these products soared to all-time highs as Western sanctions have disrupted oil exports from Russia, the world's top crude and products exporter combined, while global inventories are at multiyear lows.