Indian Refiners and Energy Major Plan to Avoid Iran-Blacklisted Ships Amid Security Concerns

At least three Indian oil refiners and a global energy major plan to stop using vessels included on Iran's new blacklist, including for ship-to-ship (STS) transfers, due to growing security concerns. Four sources with direct knowledge of the matter confirmed the development.

The move follows an announcement by Tehran on Sunday introducing a blacklist of 45 ships that it claims have broken rules for crossing the Strait of Hormuz. Iran stated it would take action against any vessels transferring loads with the blacklisted ships, escalating threats over the critical waterway for global energy supplies six months into the U.S.-Israeli war on Iran.

Iran's announcement appears aimed at impeding shuttle runs conducted by Gulf oil producers, such as the United Arab Emirates and Saudi Arabia. These producers have used dedicated tankers to move oil from the Gulf through Hormuz for unloading via STS transfers in the Gulf of Oman onto ships bound for end-users. These shuttle runs have sustained oil flows from the Middle East that were previously curtailed by Iran's clampdown on shipping through the strait.

According to a post on the social media platform X by the Persian Gulf Strait Authority—a new body established by Iran to manage the strait—named vessels could face fines, detention, and cargo confiscation. Sources speaking on condition of anonymity due to the sensitivity of the issue confirmed precautions are underway.

"We will avoid our chartered vessels dealing or STS or anything to do with non-compliant ships for Middle Eastern cargoes," said a source working at an Indian refinery.

Some of the tankers listed by Iran are owned or chartered by Saudi Aramco and Abu Dhabi National Oil Co (ADNOC). Shipping data shows these vessels have been used to shuttle crude, refined products, and liquefied natural gas (LNG) out of the Gulf for STS transfer off Fujairah in the UAE or Sohar in Oman. Both Saudi Aramco and ADNOC declined to comment on the matter.

Ana Subasic, a trade risk analyst at shiptracking firm Kpler, noted that compliance-sensitive buyers are expected to avoid these vessels moving forward. However, she suggested the trade is more likely to reroute through alternative tonnage, counterparties, or transfer locations rather than disappear completely.

Multiple trade and shipping sources report that several charterers and shipping firms are internally evaluating Iran's warning and discussing whether to continue STS operations. A Gulf crude buyer indicated it would be safer to purchase oil on a delivered basis shipped directly to a final destination, rather than free-on-board at STS locations in the Gulf of Oman.

Formosa Petrochemical Corp President KY Lin stated that internal departments are still discussing how to proceed with long-term crude deliveries from the Strait of Hormuz via ship-to-ship transfers. Iran has previously attacked several tankers in the region, including the Wedyan, Mombasa B, and Al Bahyah.

Data following the blacklist release showed that two of the 12 very large crude carriers on the list stopped giving their location through automatic identification systems (AIS) by Tuesday, while the rest have had their AIS transponders switched off for weeks.

Highlighting the broader market implications, Subasic added that contagion is a key issue. If Iran follows through on threats to penalize vessels conducting STS transfers with blacklisted tankers, the pool of willing shipowners, charterers, and buyers will narrow—particularly among firms with material Gulf exposure—while increasing due-diligence requirements and potentially raising freight, insurance, and risk premia.

"Geopolitical disruptions in critical trade routes like the Strait of Hormuz immediately impact global supply chains and operational risk management. When key logistics arteries face regulatory and security threats, energy companies and refiners must swiftly adapt their procurement strategies, evaluate compliance, and factor in rising insurance and freight costs. Managing supply chain contagion is essential for maintaining business continuity during periods of heightened regional conflict." — Dr. Shishir Gupta, Founder & CEO, StartupLanes