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Aristeo Lopez draws on more than two decades of international trade and investment arbitration experience. His practice extends to investment, international arbitration, services, trade remedies, government procurement, international negotiations, and market access for goods.

Aristeo assists companies in the United States and Mexico to manage the challenges and opportunities under the United States-Mexico-Canada Agreement (USMCA). He also assists a government to access one of the world’s largest free trade regions and negotiate a bilateral free trade agreement.

In addition, Aristeo serves clients in matters relating to Investor-State Dispute Settlement (ISDS). He blends his experience as negotiator of investment agreements and counsel in several investment arbitrations under the North American Free Trade Agreement (NAFTA), USMCA, and bilateral investment treaties (BITs).

Before joining Clark Hill, Aristeo served for more than 20 years in senior legal and policy roles at the Ministry of Economy of Mexico. From 2014-2021, Aristeo served as a counselor at the Embassy of Mexico in Washington DC. In that role, he acted as lead negotiator of the investment and government procurement chapters of the US-Mexico-Canada Agreement (USMCA). Also, he provided legal advice in the negotiation of energy, services, and dispute settlement disciplines for that agreement. In addition, Aristeo acted as counsel in multiple investment arbitrations and represented Mexico before the US Department of Commerce (DOC), the US International Trade Commission (ITC), the US Department of State, and the Office of the United States Trade Representative (USTR).

From 2008-2014, Aristeo served at the Ministry of Economy of Mexico as deputy general counsel for international trade. In that role, he acted as lead counsel to Mexico in multiple investment arbitrations arising under the NAFTA Chapter Eleven and Bilateral Investment Agreement. He also provided legal advice on international trade and investment negotiations and foreign trade matters under World Trade Organization (WTO), the NAFTA, the Comprehensive and Progressive Agreement for Trans-Pacific Partnership (CPTPP) (formerly known as Trans-Pacific Partnership), other international agreements, and BITs.


LL.M., Georgetown University Law Center, Washington, DC
Insituto Tecnológico Autónomo de México (ITAM), Diploma - Legal Aspects of International Trade
Escuela Libre de Derecho de Puebla, A.C., Bachelor of Laws, (LLB)


Customs and International Trade Bar Association

Asociación Latinoamericana de Arbitraje (ALARB) (Latin American Arbitration Association)

American Society of International Law (ASIL)



State Bar Licenses

Mexico, Licensed to practice as Special Legal Consultant in the District of Columbia


Aristeo acted as counsel to Mexico in the following trade matters:*

  • Assisted in the negotiation and implementation of the 2014 and 2020 Agreements suspending the countervailing duty (CVD) investigation on sugar from Mexico between DOC and Mexico.
  • Represented Mexico in the administrative reviews and 2019 sunset review of the agreement suspending the CVD investigation on sugar from Mexico from 2015-2020.
  • Represented Mexico before the DOC in the monitoring and compliance of the 2019 Agreement suspending the antidumping investigation on tomatoes from Mexico.
  • Provided legal advice to Mexico and the Mexican industry in multiple investigations before the ITC on perishable goods, such as blueberries, cucumbers, and squash.
  • Provided legal advice to public and private entities on international trade matters arising under the NAFTA, WTO, and other international agreements on market access for goods and services, investment and regulatory compliance.

Aristeo acted as lead counsel in investment arbitrations under the NAFTA and the Bilateral Investment Treaty between Mexico and Spain (selected matters):*

  • B-Mex, LLC, and others v. the United Mexican States (ICSID Case No. ARB(AF)/16/3),
  • KBR, Inc. v. the United Mexican States (ICSID Case No. UNCT/14/1),
  • Lion Mexico Consolidated LP v. the United Mexican States (ICSID Case No. ARB(AF)/15/2),
  • Telefónica S.A. v. the United Mexican States (ICSID Case No. ARB(AF)/12/4),
  • Abengoa, SA y COFIDES, SA v. the United Mexican States (ICSID Case No. ARB(AF)/09/2), and
  • Cargill Inc. v. the United Mexican States, ICSID Case No ARB(AF)05/2.



  • Speaker “Trade, Labor Rights, and Forced Labor – Recent Trends in International Trade Law”, International Law Weekend 2023, International Law Association – American Branch, New York City, October 2023.
  • Speaker “From Metalclad to Ruby River Capital LLC: Mexico’s NAFTA Experience and the Future of Investment Arbitration under the USMCA”, Washington Arbitration Update 2023, Mexico City, May 2023.
  • Speaker, “USMCA Dispute Resolution Mechanisms and their Impact on Energy, the Environment, and Labor Markets,” American Society of International Law (ASIL) – International Economic Law Interest Group Biennial Conference, Fort Worth, Texas, September 2022.
  • Speaker, “Territory, Tribe, and Trade: The symbiotic relationship between States and individuals in State-State dispute settlement,” ASIL, Washington D.C., April 2022.
  • Speaker “USMCA Tools to Protect Foreign Investment in Light of Mexico’s New Energy Policies”, Clark Hill webinar, January 2022
  • Speaker “USMCA: Dialogue with the negotiation team,” American Chamber (Mexico), October 2021
  • Speaker “Trends and latest developments in investment arbitration from the perspective of ICSID, UNCITRAL and the situation in Mexico,” May 2021
  • Speaker “Supply Chain Agreements and USMCA: Rules of Origin Requirements, Labor Enforcement, De Minimis Levels, Sunset Clause,” December 2020.
  • Speaker, “USMCA: Investor-State Dispute Settlement,” Ministry of Economy (Mexico), July 2020
  • Speaker, “The US Mexico Canada Agreement (USMCA)-NAFTA 2.0 – What Every In-House Counsel and General Practitioner Needs to Know”, Practising Law Institute, June 2020

* Matters handled prior to joining Clark Hill