Some oil companies to avoid ships on Iran blacklist, sources say

• Iran's blacklist targets ships used by Saudi Aramco and ADNOC for 'shuttle runs' that move oil through the Strait of Hormuz for STS transfers in the Gulf of Oman, threatening fines, detention, and cargo confiscation
• Two of 12 blacklisted very large crude carriers stopped broadcasting their locations via AIS systems after the announcement, while others had already switched off transponders for weeks
• Analysts expect compliance-sensitive buyers to avoid blacklisted vessels, but predict trade will likely reroute through alternative tonnage and locations rather than cease, while potentially increasing freight, insurance, and risk premiums

Market Summary: Iran Blacklists 45 Ships, Disrupting Gulf Oil Flows

Key Development: Iran announced Sunday a blacklist of 45 vessels allegedly violating Strait of Hormuz transit rules, threatening fines, detention, and cargo confiscation for any ships conducting transfers with blacklisted vessels. This escalation comes six months into the U.S.-Israeli conflict with Iran.

Company Response: At least three Indian refiners and one global energy major will stop using blacklisted vessels for ship-to-ship (STS) transfers due to security concerns. Saudi Aramco and ADNOC—whose owned or chartered vessels appear on the list—declined to comment. Taiwan's Formosa Petrochemical Corp confirmed internal discussions on how to proceed with crude deliveries from the strait.

Operational Impact: The blacklist targets vessels conducting "shuttle runs" for Gulf producers (UAE, Saudi Arabia) that transport crude, refined products, and LNG through Hormuz for STS transfers off Fujairah (UAE) or Sohar (Oman). These operations have maintained Middle East oil flows despite Iran's shipping restrictions. By Tuesday, two of 12 blacklisted Very Large Crude Carriers (VLCCs) disabled their automatic identification systems (AIS), with others having transponders switched off for weeks.

Market Implications: While compliance-sensitive buyers will avoid blacklisted vessels, analysts expect trade to reroute through alternative tonnage and transfer locations rather than cease entirely. However, the "contagion" effect could narrow the pool of willing shipowners and charterers, particularly those with significant Gulf exposure, while increasing due-diligence requirements and driving up freight, insurance, and risk premiums.

Critical Context: The Strait of Hormuz is a vital waterway for global energy supplies. Iran has previously attacked several listed tankers.