Team
Professionals with sector expertise and personal commitment.
Our firm is made up of professionals with solid experience in mining, energy, contracts, litigation and corporate advisory, committed to a technical, close and practical legal practice focused on each client's concrete needs.
Partner
Mario Luis Castelli Temer
Attorney and Prosecutor from the National University of Córdoba. With nearly 40 years of uninterrupted professional practice since 1988, he holds recognized experience in mining, hydrocarbons, administrative and environmental law. Founding partner of the firm since 2002, he has built a sustained practice in integral counsel for companies tied to strategic sectors. He has advised and represented domestic and international mining and energy companies on exploration, natural resources, hydrocarbons and regulatory matters. He served during 2023 as representative of the Province of Salta before the Argentine Institute of Mining Law (IADEM). In the public sector he has served as Secretary General of the State Railway Operator (SOFSE), legislative advisor at the Honorable Senate of the Nation, member of the COFEMA Standing Advisory Commission on Legislative Review representing the NOA region, and advisor to agencies of the Province and the City of Salta. Languages: Spanish and English.
Partner
Diego Nicolás Reston
Attorney from the Catholic University of Salta. Master in Corporate Law from Universidad Austral and Professor of Legal Sciences from the National University of Salta. With 15 years of experience, he practices in mining, corporate law, contracts, litigation and integral advisory to companies operating in Argentina. He complemented his training with a Diploma in Integral Mining Management (UCASAL) and a Diploma in Environmental Policy, Law and Management (Austral). Since 2022 he is part of the research project “The New Profile of the Lawyer in Dispute Resolution.” He serves as adjunct professor in General Theory of Obligations and in Damages and Liability Law, and as professor in the Diploma in Sustainable Mining, Professional Practice, and Natural Resources Law and Environmental Protection (Mining Contracts) at the Catholic University of Salta. He is a member of the legal area commission of the Mining Chamber of the Province of Salta. Languages: Spanish and English.
Attorney
Luciano Martín Castelli
Attorney from the National University of Córdoba. Diploma in Mining Law and Business Management from the Catholic University of Salta. He complemented his training with postgraduate studies in "Law and Energy: Hydrocarbons" at Universidad Torcuato Di Tella, and a specialization in Legal English at Universidad Austral. His practice focuses on mining and international law. Languages: Spanish and English.
Attorney
Constanza María Vidal Martearena
Attorney from the Catholic University of Córdoba. She complemented her training with mediation studies at the University of Buenos Aires, local content and court practice updates at the School of the Magistracy, and a Diploma in Mining Law and Business Management at the Catholic University of Salta. She practices in contractual, mining and immigration matters. Her experience includes work at law firms in Córdoba and Salta; since 2024 she has been part of the firm, with involvement in mining, corporate and immigration law. Languages: Spanish and English.
Associate
Cesar Solveyra
Attorney from the Catholic University of Salta, with a solid track record advising companies on civil, commercial and labor law between 2015 and 2022. Since 2020 he has focused his practice on the mining industry, specializing in regulation, contracts and the management of legal matters related to mining operations in Argentina. He is familiar with the mining regulatory framework of Salta, Jujuy and Catamarca. He has experience supporting mining projects across their different stages, having worked at Posco Argentina S.A.U. (2020–2022) and, since 2022, in the legal department of Mina Pirquitas S.A. (SSR Mining), where he currently serves as Manager of Legal and Public Affairs. He has also served as Vice President of the Mining Chamber of Jujuy since 2022. His practice focuses on contract negotiation, regulatory compliance, government and community relations, and stakeholder management, with a particular emphasis on risk mitigation and legal support for operational continuity and the development of long-term projects.
Associate
Simón Mariño Cornejo
Attorney from the Catholic University of Salta, with more than 10 years of professional experience. He holds a Diploma in Labor Law and Industrial Relations and a Diploma in Civil Procedural Law and Oral Litigation, both from Universidad Austral. His practice has focused primarily on labor law, human resources, union matters, contracts and industrial relations. He also has experience in health law and civil and commercial litigation, combining contentious practice with corporate advisory. Languages: Spanish and English.
Associate
Teodoro Becker
Attorney from the Catholic University of Salta, with more than 10 years of experience in the public and private sectors. Master in Private Law with a focus on Corporate Law (UNSa – FCEJS). He has experience in litigation, complemented by solid training in administrative and civil law, particularly in contractual, commercial, property rights, registry law and inheritance matters. His postgraduate training includes diplomas in Contracts, Mining Law, Integral Mining Management, Registry Law and Civil Procedural Law. He currently serves as Head of the Legal Department of the General Directorate of Real Estate of the Province of Salta, leading a team of attorneys, notaries and administrative staff, while also practicing privately. His career combines institutional legal management, academic training and professional experience in complex matters. Languages: Spanish and English.
Of Counsel
Daniel Zamora
Attorney from the Universidad del Norte Santo Tomás de Aquino (Tucumán). Master in Corporate Law and Master in Tax Law from Universidad Austral. With more than 10 years of experience, he develops his practice in integral advisory to companies, with a special focus on tax matters, covering tax and estate planning, efficient business structuring, and tax defense in administrative and judicial proceedings before municipal, provincial and national agencies. He also holds solid experience in corporate law, including the formation and reorganization of companies, drafting and negotiation of commercial contracts, and assistance in complex corporate and commercial disputes. He has published articles in specialized law journals. He currently serves as Statutory Auditor of Camyen S.E. Languages: Spanish and English.