Three Crowns has been ranked in Band 1 for both Commercial Arbitration and Investor-State Arbitration in the Chambers UK 2025 rankings, maintaining its status as a top tier firm. Constantine Partasides KC, Gaëtan Verhoosel KC, Reza Mohtashami KC, and Leilah Bruton have been individually ranked. The firm has also maintained its leading ranking in the Public International Law Guide.
“ACCLAIMED INTERNATIONAL ARBITRATION OUTFIT WITH AN IMPRESSIVE CLIENT ROSTER”
In their review, Chambers describes Three Crowns as “an acclaimed international arbitration outfit with an impressive client roster” and highlights the firm’s deep “expertise in both commercial arbitrations and investor-State disputes”. One source notes that “Three Crowns is top class when it comes to strategy and execution”, with another adding that they are “masters at what they do”. Another commentator emphasises that Three Crowns has “excellent expertise, extensive knowledge of the subject matter and an understanding of the client’s strategic objectives”. Our team is recognised as “very sharp” with “an appetite for out of the box thinking”.
The firm has also been recognised for its work in public international law. Chambers highlights its “strong pedigree in public international law matters”, noting that “the firm fields a bench of highly esteemed practitioners in this area”.
“FIELDS A HEAVYWEIGHT TEAM OF ARBITRATION SPECIALISTS”
CONSTANTINE PARTASIDES KC
Constantine is one of only two practitioners identified as a “Star Individual” in the arbitration guide, the highest ranking in Chambers. The publication describes him as a “highly esteemed arbitration specialist acting for top-echelon clients in complex commercial and investment treaty disputes”. Sources highlight the quality of Constantine’s oral advocacy, noting that his “great strengths are in his oral advocacy, leadership and presence” and that he is “really compelling”. Another adds that “he is able to get to the bottom of a case, simplify and present it to the court”, describing him as “a class act”. He has also been ranked for his work in public international law, with Chambers noting that he is “well known for acting in high-value disputes under bilateral and multilateral investment treaties around the world”. Constantine has appeared as appeared as lead counsel in some of the largest international arbitrations of the last two decades. He is a Member of the ICCA Governing Board and a Director of the LCIA Board.
GAËTAN VERHOOSEL KC
Gaëtan maintains his Band 1 ranking in this year’s arbitration edition, with Chambers highlighting that he “has earned an excellent reputation” for his “extensive commercial and investor-state practice”. One source emphasises that his “capacity to grasp the big picture is unique” and that his “attention to detail and client needs is excellent”. Another commentator notes that Gaëtan is “very strategic, sophisticated, and responsive”. Gaëtan also maintains a leading ranking in public international law. He has over 20 years of experience serving as advocate or arbitrator in both commercial and investment treaty arbitrations where significant financial recoveries were at stake or novel legal issues raised. He is a member of the SIAC Court of Arbitration and was appointed to the ICSID Panel of Arbitrators by the Kingdom of Belgium.
REZA MOHTASHAMI KC
In maintaining his leading ranking again this year, Chambers notes that Reza acts in “high-value disputes” with a “particular focus on the Middle East”. One source highlights that Reza is “very good and extremely responsive”, adding that he “is very strategic in setting up a defense and handling the counterparties”. He has represented clients as counsel and advocate in more than 90 arbitrations conducted under a variety of arbitration rules in many different jurisdictions. Reza has particular expertise in disputes arising in emerging markets and is a highly sought-after specialist in the Middle East, with a focus on the telecoms, energy, and infrastructure sectors. Reza is a trustee of the Bahrain Chamber of Dispute Resolution, a member of the LCIA Court, and an editorial board member of Global Arbitration Review.
LEILAH BRUTON
Leilah has been newly recognised in this year’s guide for international arbitration, in which Chambers notes that she is “experienced in acting for clients in a range of jurisdictions and under a variety of different arbitral rules”. One source highlights that she “has expert logic in her reasoning”, with another adding that she is “experienced, responsive to client needs and professional”. Leilah has extensive experience representing corporations on the resolution of complex disputes involving investment treaties and contractual relationships, with a particular focus on disputes in the oil & gas, mining, and telecoms sectors.