Global commodity trading firm Mercuria, the owner of one of the world's top marine fuel suppliers, has warned of the potential for major hubs to run out of fuel oil within months because of the Middle East conflict. 

Mercuria believes shortages could potentially shut down as much as 10% of the global fleet, price reporting agency S&P Global Commodity Insights reported on Thursday, citing comments from Larry Johnson, the firm's global head of freight.

Johnson sees regional stock-outs of marine fuel oil by July, and potential outages at major hubs by August or September at the latest, according to the report.

Mercuria is the owner of Minerva Bunkering, one of the world's largest bunker suppliers. Minerva sold about 16.2 million mt of bunker fuel last year, according to Ship & Bunker's Top Ten Bunker Firms for 2026 report, equivalent to about 6.5% of global consumption.

The dramatic slowdown in traffic through the Strait of Hormuz since the outbreak of conflict in and around Iran at the end of February has shut down significant amounts of crude and refined products supply in the region, as well as cutting off the rest of the world from this oil.

In refined product markets the biggest reaction has been in middle distillates, with Middle Eastern refineries a key producer of these products and Asian refineries - also a major source of distillates - cut off from their normal supply of crude from the Middle East.

With refineries around the world rushing to maximise middle distillate supply where possible in response, more residues are being used in FCC units to increase distillate output, cutting bunker fuel supply.

While Mercuria is warning of the potential for shortages, market prices for bunker fuels have yet to reflect this.

Ship & Bunker's G20-VLSFO Index of VLSFO prices at 20 leading locations stood at $864.50/mt on Wednesday, down by 17.9% from its recent peak on March 20 - albeit 59.1% higher than its pre-war level on February 27. The index's premium to Brent crude stood at about $128/mt on Wednesday, down from a peak of $313/mt on March 23 and up from a $5/mt discount on February 27.

But while outright prices show no immediate concerns, spreads between fuel oil and distillates support the narrative of distillate output being increased at fuel oil's cost. The G20-VLSFO Index stood at a $478/mt discount to the G20-MGO Index on Wednesday, compared to a recent peak discount of $871.50/mt on April 7.

Earlier in the conflict, former IBIA Chairman Constantinos Capetanakis warned of the potential for price reaction to the Middle Eastern situation to be overdone as a means of the industry increasing its profits.

"It's much more expensive - we're talking about serious profiteering here - but there is no supply tightness in the sense that one cannot get it if you have the money to buy it," Capetanakis told Ship & Bunker in late March.

"The herd mentality has taken centre stage."