José A. Martínez de Hoz is a founding partner of Martínez de Hoz & Rueda (MHR), a leading Argentine law firm, where he leads the Energy and Arbitration groups. He has extensive experience in investment and commercial arbitration, notably acting as counsel in major ICSID cases involving Argentina, including Abaclat, El Paso, and Mobil. He also serves as arbitrator in cases across sectors such as energy, mining, telecoms, and construction under ICSID, PCA, and ICC rules. A former member of the ICC International Court of Arbitration (2013–2021), he is listed as arbitrator by several institutions including the BVI IAC and ICDR. He is recognized by Chambers, Client Choice, and is a member of AIPN and CARAT.