Ari D. MacKinnon’s practice focuses on disputes matters in Latin America with a particular emphasis on international arbitration and corruption issues. 

Ari has successfully represented a number of major Latin American oil and gas, energy, infrastructure, and pulp and paper companies as well as other clients in disputes in the region. He speaks regularly in Latin America on topics related to arbitration and crisis management. Ari has experience conducting arbitration and corruption-related reviews in both English and Spanish. 

Ari joined the firm in 2009 and became a partner in 2015.

Notable Experience

International Arbitration

  • A major Latin American oil and gas company in the successful prosecution of a Spanish-language IACAC arbitration relating to a concession agreement governed by Peruvian law.

  • Latin American affiliates of international oil and gas companies in an ongoing ICC arbitration in New York relating to the interpretation of a gas sales agreement.

  • Latin American glass manufacturer in an ICC arbitration and related civil litigation concerning the interpretation of an exclusive sales agreement.

  • Latin American oil and gas company in an ICC arbitration related to breaches of representations and warranties in an asset sale agreement.

  • Western Digital’s SanDisk subsidiary in the successful pursuit and settlement of three separate ICC arbitrations against Toshiba arising out of Toshiba’s efforts to sell its stake in the parties’ multibillion-dollar NAND flash memory joint ventures without SanDisk’s consent, and related injunction proceedings in California state court.

  • A Singapore-based maker of semiconductor products in an arbitration in connection with patent license disputes and indemnity claims.

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Enforcement and Investigations

  • An international financial institution in parallel investigations being conducted by, among others, the UK Financial Conduct Authority, the U.S. Department of Justice, and the U.S. Commodity Futures Trading Commission, relating to the FX market; also counsel to the same institution in regulatory investigations in the U.S. related to the setting of the ISDAFIX.

  • FCPA and corporate governance advice to a Mexican construction company in connection with an investigation by the CNBV and potential investigation by the SEC.

  • Advice concerning the design and enhancement of anti-corruption policies and internal controls for a Latin American pulp and paper company and a petroleum company.

  • Advice concerning the enhancement of compliance policies and procedures for international financial institution in connection with regulatory investigations of alleged attempted manipulation.

  • Alpha Natural Resources, Massey Energy Company, and Performance Coal Company in reaching a comprehensive settlement with the U.S. Department of Justice resolving potential corporate, criminal, and civil liability related to the Upper Big Branch Mine tragedy, in which 29 miners died.

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Other Litigation

  • BNP Paribas in clawback actions brought by the Trustee of the Madoff Estate in connection with the Bernie Madoff Ponzi scheme.

  • Alpha Natural Resources and certain of its directors and officers in a successful motion to dismiss a federal securities law class action brought under Section 11 of the Securities Act.

  • American Express Co. in successfully securing dismissal of shareholder derivative litigation brought in New York State court.

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Selected Activities

  • Member, Board of Directors and Program Committee, New York International Arbitration Center
  • Member, Chartered Institute of Arbitrators
  • Member, International Arbitration Club of New York
  • Member, Association of International Petroleum Negotiators


The New Supplemental Arrangement Concerning Enforcement of Arbitral Awards between Mainland China and Hong Kong,” Cleary Gottlieb Alert Memo, August 25, 2021

Ecuador Signs the ICSID Convention, What That Means for Ecuador and the Rest of South America,” Cleary Gottlieb Alert Memo, August 9, 2021

Second Circuit Reinforces Its Approach To Section 1782 While U.S. Supreme Court Case On Application Of Section 1782 To Private International Arbitration Remains Pending,” Cleary Gottlieb Alert Memo, July 19, 2021

The Scope of Immunity for International Organizations Comes Under Scrutiny Again, Two Years After the U.S. Supreme Court’s Decision in Jam v. International Finance Corporation,” Cleary Gottlieb Alert Memo, March 1, 2021 

2020 Revision of the IBA Rules on the Taking of Evidence in International Arbitration,” Cleary Gottlieb Alert Memo, February 17, 2021 

The London Court of International Arbitration Releases Updated Arbitration Rules, Emphasizing Efficiency,” Cleary Gottlieb Alert Memo, October 26, 2020 

Circuit Split Intensifies Over Use of 28 U.S.C. § 1782 to Obtain Discovery for Use in Private International Arbitration,” Cleary Gottlieb Alert Memo, July 13, 2020 

Supreme Court Holds That New York Convention Does Not Preclude Non-Signatories From Invoking State Law Principles To Compel Arbitration,” Cleary Gottlieb Alert Memo, June 3, 2020 

Most EU Member States Agree to Terminate Their Intra-EU Bilateral Investment Treaties,” Cleary Gottlieb Alert Memo, May 7, 2020

U.S. District Court Denies Section 1782 Discovery for Use in DIS Arbitration, Highlighting Deepening Circuit Split on Statute’s Applicability to Private Commercial Arbitrations,” Cleary Gottlieb Alert Memo, April 3, 2020

Second Circuit Overturns Arbitration Award Against Non-Signatory Parent Company,” Cleary Gottlieb Alert Memo, April 3, 2020

COVID-19 and the Tolling Of Statutes of Limitations: Impact on Arbitrations Seated in New York,” Cleary Gottlieb Alert Memo, March 25, 2020

3 NY Contract Law Concepts In The Context Of Coronavirus,” Law360, March 4, 2020

Potential End of Suspension of Title III of the Helms-Burton Act: Authorization of Claims Under U.S. Law for “Trafficking” in Certain Cuban Properties,” Cleary Gottlieb Alert Memo, February 26, 2019

Supreme Court Confirms Arbitrators Decide Threshold Issues,” Cleary Gottlieb Alert Memo, January 9, 2019

40 Under 40 International Arbitration (2018), July 12, 2018

“A Reassuring 2nd Circ. Approach To Annulled Awards,” Law360, July 28, 2017

Drafting International Arbitration Clauses,” THĒMIS-Revista de Derecho, March 26, 2017

Second Circuit Confirms That an Arbitral Award That Has Been Nullified at the Seat of the Arbitration Should Rarely Be Enforced,” July 27, 2017

Second Circuit Rules That FSIA Provides Sole Basis for Jurisdiction Over Foreign Sovereigns in Actions to Enforce ICSID Awards,” July 17, 2017