Howard S. Zelbo’s practice focuses on international commercial and investment arbitration and complex cross-border litigation.

He has particular experience with handling arbitrations concerning the Latin American region and other emerging markets, as well as international disputes involving sovereign governments and entities.

Howard has served as the lead attorney in numerous international arbitrations seated around the globe and administered by all of the major international arbitration institutions, including the International Chamber of Commerce, the London Court of International Arbitration, the International Centre for Dispute Resolution, the Stockholm Chamber of Commerce, and the International Centre for Settlement of Investment Disputes. He has extensive experience with multijurisdictional dispute resolution, including coordinating simultaneous international arbitration and foreign court proceedings and working closely with lawyers from around the world to tackle complex questions of international law.

His practice spans a variety of industries and sectors, including mining, energy, construction, telecommunications, port management, finance, mergers & acquisitions, insurance, and real estate. He also has been involved in numerous purchase price adjustment disputes, as well as proceedings to enforce or annul arbitral awards, compel arbitration, and obtain provisional relief in aid of arbitration.

Howard joined the firm in 1988, became a partner in 1994, and became a senior counsel in 2021.

Notable Experiences

International Arbitration

  • Western Digital subsidiary SanDisk in a high-stakes ICC arbitration against Toshiba governed by Japanese law regarding the transfer of consent rights in joint ventures worth billions of dollars.

  • A manufacturer and marketer of defense electronics and laser technology products in a pending ICDR arbitration against a business partner relating to laser medical technology and governed by New York law.

  • A European retailer in a merger-related ICC arbitration with over $150 million at stake, seated in São Paulo and governed by Brazilian law.

  • Citigroup Venture Capital in its widely publicized battle for corporate control over Brasil Telecom, which included ICC arbitrations in London and in Paris and litigation in the Southern District of New York.

  • DP World in an arbitration against Peru relating to a port concession.

  • Kookmin Bank in defending a multimillion-dollar ICC arbitration.

  • The Dominican Republic in an ICC arbitration brought by a Netherlands Antilles company on contracts to provide security services.

  • The Latin American affiliates of international oil and gas companies in an ICC arbitration in New York relating to a dispute under a gas sales agreement.

  • The Republic of Argentina, together with the Procuración del Tesoro de la República Argentina, in claims brought at ICSID under the Argentina-Italy bilateral investment treaty by holders of interests under multiple Argentine bonds.

  • Goodyear in an arbitration relating to its principal European subsidiary.

  • A major Argentine oil and gas corporation in a dispute with an oil trading company to which it sells LNG under an English-law governed contract, involving an ICC arbitration in New York and injunction proceedings in the UK.

  • Several companies in purchase price adjustment arbitrations, including obtaining a $70 million purchase price adjustment award in favor of a French company.

  • The former CEO of a large privately held European real estate company relating to the exercise of put rights.

  • A Mexican corporation obtaining a favorable settlement in an arbitration concerning an alleged breach of a copper concentrate supply contract.

  • An Argentine company in obtaining a favorable pre-arbitration settlement of a dispute relating to a liquid natural gas supply contract.

  • A Brazilian mining company in a matter in which the company was indemnifying the prevailing party in an arbitration under Brazilian law.

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Commercial Litigation

  • BHP Billiton litigation arising out of  its $40 billion all-cash offer to acquire Potash Corporation of Saskatchewan.

  • Nortel Networks International in connection with a $7 billion dispute relating to the allocation of proceeds from the sale of substantially all of Nortel’s operations and patent portfolio.

  • Warburg Pincus in connection with litigation arising out of its takeover of Rural/Metro Corporation.

  • Genting New York and Kien Huat Realty in winning complete dismissal of complaint alleging conspiracy and monopolization claims relating to the operation of a casino in New York, and successfully defending this decision in the Court of Appeals for the Second Circuit, which affirmed on all counts.

  • Deutsche Bank AG and UBS AG in a multijurisdictional battle (Brazil, New York, and London) to collect on an over $150 million defaulted loan facility against Intelig Telecomunicações Ltda.

  • Petroandina, a subsidiary of Pluspetrol, in two separate litigations in Delaware Chancery Court against Harvest Natural Resources arising out of the parties’ investments in Venezuela through a jointly-held corporation. Obtained preliminary injunctions in both litigations against Harvest, preventing its threatened breaches of the parties’ shareholder agreement.

  • Citigroup in litigation arising out of one of the largest-ever foreign currency trading frauds.

  • lnterpublic Group in connection with a formal, six-year investigation by the Securities and Exchange Commission relating to the corporation’s restatement of earnings.

  • Del Monte Foods Corporation in obtaining partial summary judgment in a complex commercial case that led to a favorable settlement of the remaining claims.

  • Norwegian Cruise Lines in winning the dismissal of securities claims.

  • The New York State Banking Department in connection with the financial collapse of BCCI.

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  • Member, The International Arbitration Club of New York
  • Former Member of the Advisory Committee, The International Institute for Conflict Prevention & Resolution
  • Former Chairman, Securities Litigation Committee, New York State Bar Association


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

COVID-19: Public Health Emergency Measures and State Defenses in International Investment Law,” Cleary Gottlieb Alert Memo, April 28, 2020

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

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

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

U.S. Supreme Court Holds That State Courts Lack Specific Personal Jurisdiction to Entertain Non-Residents’ Claims for Injuries Not Connected to In-State Conduct, June 20, 2017

U.S. Supreme Court Reaffirms That Corporate Defendants Are Subject to General Personal Jurisdiction Only Where They Are “At Home,” May 30, 2017 (republished in the Harvard Law School Forum on Corporate Governance and Financial Regulation on June 14, 2017)

U.S. Supreme Court: Hague Service Convention Permits Service of Process by Mail, May 23, 2017

Supreme Court Adopts Exacting Approach to Jurisdictional Inquiry Under FSIA’s Expropriation Exception, May 2, 2017

The Year in Review: An Annual Survey of International Legal Developments, Chapter on International Litigation, ABA/Section of International Law, Vol. 51, 2017

“International Discovery” in The Year in Review, The International Law Section of the American Bar Association

“Arbitration Jursidiction-by-Jursidiction Survey,” Lexology Navigator, Consulting Editor (2013-14)

“Supreme Court Upholds Class Arbitration Waivers,” Columbia Law School’s Blog on Corporations and the Capital Markets (April 14, 2013)

“U.S. Supreme Court Limits the Ability of Arbitrators to Order Class Arbitration,” Mealey’s International Arbitration Report (June 1, 2010)

“When Is an Arbitration Award Actually Final?” The National Law Journal (May 31, 2010)

“International Litigation: Year in Review,” International Lawyer (June 18, 2009)

“Third Party Discovery in International Arbitrations,” New York Law Journal (April 13, 2009)