Overview
On August 21, 2025, the U.S. Department of the Treasury's Office of Foreign Assets Control ("OFAC") announcedfurther sanctions action targeting a global network facilitating Iranian oil exports. The action was taken pursuant to Executive Order ("E.O.") 13902, and designates Greek national Antonios Margaritis ("Margaritis"), his affiliated companies, and nearly a dozen vessels for their role in allegedly transporting Iranian petroleum products in violation of U.S. sanctions programs on Iran.
Similar to previous sanctions actions against Iran, the latest designations are taken pursuant to Executive Order 13902 and in furtherance of National Security Presidential Memorandum 2, which directs a campaign of maximum economic pressure on Iran. We previously reported on sanctions action against Iran in our August 13 post, which detailed ongoing efforts by OFAC to dismantle Iran's financial and surveillance architecture as a part of this maximum pressure campaign.
Key Findings and Designations
Margaritis Network Designations
OFAC's action identifies a complex web of actors and assets allegedly involved in Iran's "shadow fleet." According to the OFAC press report, the Antonios Margaritis Network has facilitated Iranian oil shipments for years, leveraging Margaritis's shipping industry expertise. He is now designated pursuant to E.O. 13902 for operating in Iran's petroleum sector. His affiliated entities, Marant Shipping and Trading S.A., Square Tanker Management Ltd., Comford Management S.A., and United Chartering S.A., are also designated for being owned or controlled by him.
In addition to designating Margaritis and his affiliated entities, OFAC also made a number of vessel designations pursuant to this recent action. Additional vessels part of the network identified as blocked property due to their role in transporting Iranian oil include VICTORY ARI,SONDOS,KATSUYA,LAFIT,GIANT,ADELINE G,KONGM, andARES.
Other Targeted Entities
In addition to the Margaritis designations, OFAC also targeted a number of additional Iranian oil export facilitators. Hong Kong-based U Beacon Shipping Co., Hong Kong Hangshun Shipping Limited, and Ares Shipping Limited were designated for operating vessels that have transported millions of barrels of Iranian oil to China in violation of U.S. sanctions programs. These vessels have also allegedly conducted ship-to-ship transfers with previously sanctioned tankers.
UAE-based Ozarka Shipping - FZCO, was also designated for managing vessels that conducted ship-to-ship transfers with sanctioned tankers and transported Iranian petroleum products to China.
U.S. Policy Context
In remarks following the designations, Treasury Secretary Scott Bessent stated that the action "degrades Tehran's ability to fund its advanced weapons programs, support terrorist groups, and threaten the safety of our troops and our allies." As noted above, the designations are part of an ongoing broader campaign of maximum economic pressure on Iran, consistent with National Security Presidential Memorandum 2.
Next Steps
This action underscores OFAC's continued focus on Iran related sanctions programs and secondary sanctions targeting non-U.S. actors involved in key sectors in Iran, notably the oil and gas sector. Companies in shipping, energy, insurance, and commodities trading should assess exposure to the designated entities and vessels. For further information on this recent action, and the list of individuals and entities specifically designated, please refer to the following OFAC update.
OFAC Designation Implications
As with prior OFAC designations, all property and interests in property of the designated individuals and entities that are in the United States or in the possession or control of U.S. persons are blocked and must be reported to OFAC. Entities owned 50 percent or more by one or more blocked persons are also blocked under OFAC's 50% Rule.
All transactions by U.S. persons or within (or transiting) the United States that involve any property or interests in property of designated or blocked persons are prohibited unless authorized by a general or specific license issued by OFAC or exempt. These prohibitions include the making of any contribution or provision of funds, goods, or services by, to, or for the benefit of any blocked person and the receipt of any contribution or provision of funds, goods, or services from any such person.
***
We will continue to monitor developments in this area and encourage you to subscribe to be kept informed of latest developments. Please contact the authors or your usual Herbert Smith Freehills Kramer contacts for more information.
The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.
