Estudio Ymaz

Estudio Ymaz

about us

We are

Our history

The Estudio Ymaz Abogados law firm, established in 1987 by Esteban R. Ymaz Cossio, offers a full range of legal services to companies and public entities. When it was first established, the Firm participated in several infrastructure projects, and it has consistently been expanding into new areas of law, such as Public Services, Corporate Law, Foreign Investment Protection, Energy, Litigation and Arbitration Services. Our client profile has also increasingly diversified.

Following the intellectual tradition of the Ymaz family, the Firm also excels in Constitutional Law, particularly in appeals to the Supreme Court of Justice. With the passing of time, the Firm has become a dynamic and flexible professional structure that provides services in all areas of law. The Firm’s mentor is Esteban Ymaz (1903-1981), a lawyer who graduated with honors from the University of Buenos Aires, where he was awarded a gold medal for his outstanding academic performance. He also obtained a Juris Doctor degree. Furthermore, he was a university professor of Roman Law, he acted as Court Clerk, Clerk of the Court of Appeals, and Clerk of the Supreme Court of the Argentine Republic from 1937 to 1960, and finally, he was named Justice of said Supreme Court. He was highly familiarized with the modern jus-philosophical thinking and particularly, with the “Egological Theory of Law” (also known as “Argentine Theory of Law”). As a result, his doctrine writings and some of his rulings in the Supreme Court are characterized by their originality and their respect for tradition. The general opinion is that there was an actual consubstantiation between himself and the Court.

Our experience

The Firm offers a wide range of legal services to different types of national and international corporations, organizations and entities, such as building companies, massive consumption companies, industrial companies, utility service providers, health insurance companies, free-trade zones, public service companies, regulated service companies, capital venture companies, business chambers, ministries, self-regulatory agencies, national and provincial public business entities, among others.

Our services cover negotiations, extra-judicial agreements, administrative matters, as well as judicial and arbitration proceedings (at the domestic and international level). Some of the Firm's strategies were awarded the status of leading cases in many of these areas, including the Supreme Court of the Argentine Republic. We provide high-quality legal advice. We take on clients’ problems as our own and we seek creative and innovative comprehensive solutions. We address complex cases that involve multiple jurisdictions in collaboration with other legal and non-legal professionals, since the Firm is characterized by its ability to become a Team Leader. The Firm reports directly to the client and assumes full responsibility for the entire process. It also supports clients in their search for new markets through its national and international correspondents. Our Firm gives priority to the dissemination of ideas through publications in specialized and mass media. The Firm’s lawyers have published outstanding articles on several law-related topics. Among major pieces, we could mention the following: “La Esencia de la Cosa Juzgada 2.ª Parte” (The Essence of the Res Judicatta 2nd part), by Esteban Ymaz, a collection compiled by the Firm which was published in 1996; "Protección de Inversiones Extranjeras, Tratados Bilaterales” (Foreign Investment Protection, Bilateral Treaties), by Esteban M. Ymaz Videla, published by La Ley in 1999; "El Recurso Extraordinario” (The Appeal to the Supreme Court), by Esteban Ymaz, published by Abeledo-Perrot in 2000; “El dictamen jurídico administrativo” (The Administrative Judicial Decision), by Beltrán Gorostegui, published by El Derecho in 2010; and other articles on different law-related topics published in national legal magazines.

Our vision

We are committed to providing our clients with comprehensive and customized legal services, based on the professional experience of our partners, lawyers and employees. We are characterized by taking on clients’ problems as our own and seeking creative and innovative solutions. We work hard to establish a relationship with our clients built on mutual trust, supported by each party´s human and professional quality.

We observe formal protocol, in order to guarantee authentic mutual respect. We also keep our clients updated and informed about the development of legal proceedings. We strive to provide a top-quality service in form and content. We are committed to providing personalized counseling, as well as prompt and concrete answers to all questions that may arise, and to ensuring timely and efficient delivery of the required services.

Quality Management System

Since 2005, we have had our Quality Management System certified and further recertified by the Lloyd’s Register Quality Assurance, in accordance with the requirements of ISO 9001:2000 standard, and then its successor, ISO 9001:2008, with the following scope: “Legal Solutions Design. Counselling and Lawsuits in Administrative Law, Corporate Law, Protection of Foreign Investments and related matters, including work-team leadership. Involvement in complex contracting and subsequent follow-up. Appeals to the Supreme Court. Arbitration proceedings.”

The Quality Policy of Estudio Ymaz Abogados consists in providing a comprehensive and personalized legal service, based on the personal experience of the partners, lawyers and collaborators to satisfy all the requirements of its clients and interested parties and all applicable requirements. The Quality Policy is based on the following organizational values: Ethics, Experience, Excellence, Independence, Sobriety, Tradition, Flexibility and Dynamism. The staff of the Firm is committed to the continuous improvement of the effectiveness of the Quality Management System.

our tasks

Scope of activity

Administrative Law

We have vast experience and expertise in this area of Law, especially in administrative contracts. We have actively participated in public works, public utilities and public services concession contracting (concessions, permits, licensing, privatizations under various formats), other modern forms of public contracting (public-private participation, leasing, fiduciary agreements, duty-free areas, etc.), and in classic contracting...

...of public works (in their traditional model or by adopting modern forms, such as EPC and FIDIC) as well as goods supply. The Firm’s services, which are based on our clients’ needs, start from the preliminary stages of contracts, including procedures to establish a foreign corporation in the country, joint venture agreements, or the creation of new companies. Services further include private initiatives, public-private participation, and external or internal financing proposals for the corresponding agreements, including customary procedures of contractor selection (public or private bids, and direct contracting); as well as legal control and supervision of the development of contracts, the particular contractual relationship between the Company and the State and, eventually, the Regulators, users, consumers and third parties; defense against potential sanctions, renegotiations, amendments and tariff adjustments, final receptions, and in the contingency of insuperable conflicts, their termination. Specifically, Estudio Ymaz Abogados has worked with clients from several fields, such as nuclear power plants, hydro-electric plants, thermal power plants, drinkable water, sewage, ports, posts, railways, subways, highways, routes, bridges, waterways, housing, gas pipelines, high-voltage lines, renewable and non-renewable energy, hydrocarbons, etc. Moreover, we had the honor of participating in the development of general rules and regulations within our scope of expertise in administrative contracts. The Firm’s General Director acted as Coordinator of the Argentine Ministry of Justice Committee that drafted the bill for the establishment of the Régimen General de las Concesiones, Licencias y Permisos de Servicios Públicos Nacionales y Figuras Vecinas (General Rules for National Public Service Concessions, Licenses and Permits, and Related Aspects). The value of this project has been recognized in the country´s professional, academic and political circles. As a result of our expertise in important public projects, our Firm has gained experience and provides counselling for big private building projects, industrial plants, stationary power plants, EPCs, among others, in the drafting of agreements and during the different stages of the projects, including the protection of their interests within the changing scenario and regulations of the country.

Corporate Law

Estudio Ymaz Abogados has a highly-trained team specialized in this area. We would like to highlight due diligence processes, joint venture agreements, incorporation of companies (from the drafting of corporate bylaws and registration procedures to the follow-up of the company's activity, its dissolution and liquidation), corporate issues and conflicts, contract renegotiations, modern building contracts (EPC and FIDIC), corporate financing operations...

...(in financial and capital markets), advice on equipment imports and exports, and active involvement in the development of new businesses and new business models that may arise in the market. The Firm provides advice on business contracts, either supervising the process or representing the company's interests in the dealings or agreements concerning different types of contracts, such as: transfer of technology and commercial establishments, goods supply, distribution and logistics, business representation, commercial agency, trusteeships, business purchase and sale contracts, etc. We have had the honor to participate on a draft bill for a more flexible application of joint venture agreements, the principles of which appear in the Argentine Civil and Commercial Code of 2015. The Firm has also been involved —through its member lawyers— both as arbitrator and mediator, in dealing with different corporate issues. Furthermore, we frequently prepare reports and judgments that have been acknowledged and appreciated as expressions of thorough knowledge of international and domestic law.

Constitutional Law

For the lawyers of Estudio Ymaz Abogados, the practice in this area of Law is a vocation inherited from their mentor, the Justice of the Supreme Court of the Argentine Republic Esteban Ymaz, and his most famous work El Recurso Extraordinario (The Appeal to the Supreme Court), which he wrote when he was Clerk of Court.

Due to the extensive experience our professionals have in this type of appeal, they act with sound judgement, resorting to the appeal to the Supreme Court when it is necessary. Moreover, the continuous follow-up of said Court's case law on this subject enabled the Firm to complete the third update, in the year 2000, of the aforementioned book, which is an indispensable reference for every professional who intends to bring a case to the Supreme Court. This branch of Law —and therefore, the Firm's experience in it— also includes the Amparo action (a summary proceeding for the protection of constitutional rights from direct injury), constitutional declarative action of certainty, and precautionary measures or autonomous judicial remedies to avoid irreparable damages. Thus, we have participated in important cases in which these actions were applied, in which provinces attempted to impose taxes and other fees on national projects or activities that were a matter of federal jurisdiction. One of those cases became a leading case in favor of the Firm’s clients.


Our Litigation Department deals with a great amount of lawsuits and is highly known in this location. These are different kinds of claims in which our clients are either the defendants or the plaintiffs.

To meet the requirements of those companies that carry out their activities in the entire country or in several provinces, Estudio Ymaz Abogados manages a wide network of correspondents throughout the country, in order to address the litigation needs in the different jurisdictions. When it is necessary to solve highly complex international jurisdiction disputes, the Firm relies on its specialists in International Law. Our Litigation Department stands out due to its expertise in complex proceedings. And it is also regarded for the thoroughness of its legal strategy, and for the meticulousness and thoroughness it applies at each procedural stage.

Arbitration Services

We have extensive experience in arbitration between corporations. Some arbitrations in which the Firm has intervened have been governed by the Rules of Arbitration of the International Chamber of Commerce, the United Nations Commission on International Trade Law, and the Tribunal Arbitral de la Bolsa de Comercio de Buenos Aires (Arbitration Court of the Buenos Aires Stock Exchange).

In this context, not only has Estudio Ymaz Abogados acted in defense of one of the parties, but it has also had the honor of having some of its partners appointed as party arbitrators by top international companies in such arbitrations related to very diverse business issues. In addition, our Firm introduced in the country the systematic knowledge of the Agreement on Promotion and Reciprocal Protection of Investments (APPRI) and the Bilateral Investment Treaties (BIT) as means of protection for investors. Different approaches by the Firm in this respect have been confirmed by recent arbitration awards of the International Centre for Settlement of Investment Disputes (ICSID), an international institution that manages conflict resolutions according to those international agreements. The first Argentine specialist on this subject is an associate of the Firm, and he has written a book that became a source of reference known to all those interested in the subject and that has enjoyed wide international acceptance. The knowledge and experience we have acquired on the intricacies of these Treaties, in purely legal aspects as well as the diplomatic and procedural characteristics of the arbitration provided for the solution of disputes, puts us in a strategic position to defend foreign investments. As a result, the Firm has witnessed an increase in requests for its services in this area of expertise from many foreign corporations.

Real Estate

Estudio Ymaz Abogados provides counselling and assistance in Real Estate deals. Therefore, we are familiarized with all the traditional elements of the real estate market, and we acquired experience in the generation of innovative legal instruments and structures which adapt to the current market needs.

Thus, along with our consultants, we work in collaboration with different agents in the real estate market (trusts and development companies, building companies, architects, engineers, real estate agencies, etc.), in urban development housing projects, offices or mixed-use developments, in addition to developments of gated communities and country clubs, assisting them in the planning of all stages of the projects (initial stage, building, marketing and after-sale). We also provide clients with advice and assistance in real estate investments and deals (purchase or sale, process of due diligence on the property, urban leasing, commercialization and administration).


We understand that mining companies require comprehensive services: legal, economic, technical support, etc. This sector demands follow-up throughout the entire mining project, from the exploration stage to the end of the activities and the mine remediation process.

For the provision of this service and upon the clients’ request, the Firm assigns an interdisciplinary team of professionals specialized in mining-related topics: financing, customs, taxes, land registry, the environment, among others. Regarding specifically legal matters, Estudio Ymaz Abogados leans on permanent consultants that are knowledgeable about the applicable national and provincial legislation, as well as international treaties signed by Argentina, in particular the Tratado de Integración y Complementación Minero (Mining Integration and Complementation Treaty) made with Chile.

Environmental Law

The Firm has successfully dealt with environmental law matters. Given the complexity of the subject and the different jurisdictions involved, Estudio Ymaz Abogados has forged a strong and strategic alliance with specialists in order to address these issues.

We believe that this is a very important service we make available for our clients for the development of projects of great importance and their activities in environmental areas. Through the Binational Business Chambers of countries with higher environmental protection commitment levels, the Firm actively participates in initiatives related to different techniques and regulations aimed to raise awareness among companies about the efficient means of production that protect the environment.

Tax Law

Estudio Ymaz Abogados has built an alliance with tax consultants, and it trains its own staff. Our Firm is also used to working in collaboration with the accountants or tax consultants of clients upon their request.

Both models have been used to work on several tax planning cases in order to assist in making clients operations more profitable. We offer our clients the services they need to carry out the steps required to obtain national treasury pronouncements on applications for tax exemptions, tax returns, double taxing, non-retention certificates, easy terms of payment plans, etc. Moreover, we have extensive experience in defending our clients against national, provincial and municipal government tax claims. We have intervened both before the pertinent Internal Revenue Office and the Tax Court of the jurisdiction, in resolutions, demands, summary proceedings, executions, etc., from those government agencies. When we deemed it necessary, we appealed to the competent Court of Appeal. Finally, we have also developed tax criminal defenses

Labor and Social Security Law

Estudio Ymaz Abogados serves its clients’ labor portfolios. This service covers employee issues, occupational accidents, lay-offs, relations with welfare services and labor conflicts, as well as preventive counseling, and litigations before courts of justice and the corresponding public agencies. We have consultants specialized in collective labor negotiations, conflicts at manufacturing plants, and other related issues.


We provide comprehensive advice regarding the legal aspects of the business, such as types of corporations, labor relations, trademark registration, relations with other corporations, currency inflow and outflow, currency control, etc. We present clients with the different options available from a legal standpoint for a given business, and offer them sound recommendations so that they can make the most appropriate decisions in every situation. The Firm is highly knowledgeable about business management to facilitate the connection between legal aspects and the various functional areas of every modern organization: marketing, finance, logistics, human resources, communication, and crisis management.


Estudio Ymaz Abogados is characterized by providing training within its scope of activity. Training options include in-house training courses in companies, courses at Business Chambers Training Schools, in public entities, and seminars in the Escuela del Cuerpo de Abogados del Estado (ECAE, School of the Public Body of Lawyers). We feel it is important to mention the Seminario Internacional de Infraestructura y Servicios (International Seminar on Infrastructure and Services) that we have organized together with the Argentine Catholic University every year since 2010.


experience and reputation


Esteban R. Ymaz Cossio ✝

General Director

He graduated as a lawyer from the University of Buenos Aires in 1970. He took a doctorate in General Theory of Law. After practicing in Federal Court, he started his professional career in the General Attorney´s Office of the Argentine Republic, where he worked until he became a partner in the law firm Estudio F.M. Araujo.

In 1987, he founded the law firm Estudio Ymaz Abogados and he has been General Director since then. He works in cases related to Administrative, Corporate and Constitutional Law. In addition, he is the arbitrator appointed by the Firm as its representative at the Centro Empresario de Mediación y Arbitraje (Argentine Corporate Center for Mediation and Arbitration) set up by the most prestigious law firms of Buenos Aires. He has been appointed arbitrator in the International Chamber of Commerce. He has also been appointed by international corporations as their arbitrator in a wide range of conflicts. He has extensive experience in important infrastructure projects and certain aspects of Corporate Law. He acted as member, consultant, secretary and coordinator in several government and business committees in the course of the contemporary history of law in Argentina. He has also coordinated and taught several seminars related to his area of expertise at law-related institutions, prestigious universities and business organizations. He published numerous articles on Administrative and Corporate Law in specialized publications. He has been a Permanent Professor of the Faculty of the Attorney General’s Office Lawyers School since 2009.

Esteban M. Ymaz Videla


He graduated as a lawyer from the Argentine Catholic University in 1995. He graduated with honors and obtained an award from “El Derecho” publishing house. He has a Master’s Degree in Administrative Law from the Austral University. He received the La Ley award for the best grade-point average of his class, and his dissertation was granted the Best Dissertation Award for the class of 1997.

In 1995, he became part of the law firm Estudio Ymaz Abogados and he has held the position of Director of the Administrative Law and Foreign Investments Protection Department since 2000. He has wide experience in Administrative Law, administrative contracts and foreign investments. He provides advice to public entities as well as national and international first-class companies in his areas of expertise. He has extensive knowledge of bilateral investment treaties signed by the Argentine Republic, and he provides foreign investors, binational chambers in Argentina and law firms with advice regarding the protection of their investments pursuant to the regulations and the case law of said treaties. He is a member of committees and bodies of business institutions. He has given presentations, coordinated seminars and taught courses on topics related to his areas of expertise in prestigious universities and law-related institutions, in courses, conferences, congresses, as well as in governmental and business organizations. He published numerous articles on Administrative Law matters in specialized media. He is the author of the book “Protección de Inversiones Extranjeras. Tratados Bilaterales de Inversiones. Sus efectos en las contrataciones administrativas” (Foreign Investment Protection. Investment Bilateral Treaties. Their effect on administrative contracts). He is an associate professor of Administrative Law at the Argentine Catholic University Law School. He has been an Associate Professor of the Faculty of the Attorney General’s Office Lawyers School since 2009.

Martín R. Ymaz Videla


He graduated as a lawyer from the Argentine Catholic University in 1996. He graduated with honors and obtained an award from “El Derecho” publishing house. He has a Master's Degree in Corporate Law by the Austral University. In 1996, he became part of the law firm Estudio Ymaz Abogados and he has held the position of Director of the Litigation Department since 2000.

He has wide experience in litigations and arbitrations. He is specialized in Litigation and Corporate Law and he has great knowledge of the corporate sectors’ needs. He provides national and foreign first-class companies with advice on projects which require modern ways of financing and regarding corporate rules, and the changing business and registration case law. Moreover, he acts as an advisor for business chambers. From 1994 to 1997, he was an Associate Professor in the Real Property Rights chair of Atty. Manuel Horacio Castro Hernández at the Argentine Catholic University Law School. He has also coordinated and taught different seminars related to his areas of expertise, both in law-related institutions and in prestigious universities. He published numerous articles on Commercial Law matters in specialized media.

Beltrán Gorostegui


He graduated as a lawyer from the National University of La Plata in 2000. He has a Master's Degree in Administrative Law from the Austral University (2004). He was an advisor in the Legal Undersecretariat Department of the National Ministry of Economy.

In 2003, he became part of the law firm Estudio Ymaz Abogados and he has held the position of Deputy Director of the Administrative Law and Foreign Investments Protection Department since 2006. He has wide experience in Administrative Law and administrative contracts. He provides advice to public entities and national and international first-class companies on these matters. He teaches the subject Administrative Law I at the Legal and Social Sciences Faculty of the National University of La Plata. He is an Associate Professor of the subject Administrative Law I at the Austral University Law School. He has also been a lecturer in several congresses, conferences and seminars on Public Law. He has published numerous articles on Administrative Law matters in specialized media. He is the author of the book “El dictamen jurídico administrativo” (The Administrative Judicial Decision). He has been an Associate Professor of the Faculty of the Attorney General’s Office Lawyers School since 2009.

Pablo Schlotthauer


He graduated as a lawyer from the Buenos Aires Law School University in 2017 with a additional education in legal research. He has worked at Estudio Ymaz Abogados Firm in the Litigation Department since 2018.

He has a wide experience in several type of litigation. Between 2013 and 2017 he was student assistant in the Civil and Commercial Contracts chair of Atty Oscar J. Ameal at Buenos Aires Law School University, and from 2017 to 2020 he was Associate Professor. He was lecturer in several congress and seminars of Civil and Commercial, he won an award for the best paper in the commission N°1 of XVIII Argentine Consumer Law Congress, that was celebrated in the South National University (2018). He was member in many legal research project, he was research intern between 2016 and 2017 in the Buenos Aires Law School University. He published many articles about Commercial Law in specialized media.

Other Lawyers

Ten additional lawyers complete our staff, and work in the following Departments: Administrative Law and Foreign Investments Protection, Corporate Law and Litigation; as well as permanent advisors specialized in Environmental Law, Real Estate Law, Mining, Tax Law, Customs Law and Criminal Law.

National and Foreign Correspondents

Furthermore, our Law Firm has a wide network of correspondents throughout the Argentine Republic, in the MERCOSUR countries (Brazil, Uruguay, Paraguay and Chile), and in Bolivia, Colombia, Peru, Mexico, USA, Spain and Germany.