Dr. Claudia Annacker


Dr. Claudia Annacker

Partner – Dechert LLP U.S.; Consultant – Dechert LLP Paris

Paris | 32 rue de Monceau, Paris, France 75008
+33 1 57 57 80 80 | +33 1 57 57 80 81


Dr. Claudia Annacker focuses her practice on international arbitration and litigation and public international law matters, in particular investor-State disputes, inter-State disputes, disputes involving international organizations and human rights cases. She has represented states and investors in more than 30 investment treaty arbitrations and regularly advises investors on structuring their investments to benefit from, or improve, investment treaty protections. 

Consistently recognized as a leading lawyer and expert in international arbitration by Chambers and The Legal 500, she is described as “an investment treaty specialist with a phenomenal reputation…profound practical experience and high academic knowledge of international treaty disputes,” a “strategy maestro with a unique and impressive presence in the court room” and “highly respected by tribunals and opposing counsel.” She is also noted for her “second-to-none knowledge of theory of international law and arbitration practice.” Benchmark Litigation named Dr. Annacker “Lawyer of the Year” France (2019), as well as a “Dispute Resolution Star” in international arbitration (2020). Who’s Who Legal has also selected her as a “Thought Leader.”

Dr. Annacker is an adjunct professor at the University of Vienna, where she teaches advanced research seminars in international responsibility and international dispute settlement and has been a visiting professor at the Paris Ouest Nanterre La Défense University. She has published widely in the fields of international arbitration and public international law.

  • The Hellenic Republic in an ICSID arbitration commenced by Poštová banka a.s. and its Cypriot shareholder under the Hellenic Republic-Slovak Republic and the Hellenic Republic-Cyprus bilateral investment treaties relating to sovereign bonds.
  • The Hellenic Republic in two separate ICSID arbitrations commenced by Cyprus Popular Bank Public Co. Ltd and Bank of Cyprus Public Co. Ltd under the Cyprus-Hellenic Republic bilateral investment treaty relating to measures taken to address the Hellenic Republic’s financial and sovereign debt crisis.
  • The Republic of Austria in an ICSID arbitration under the Austria-Malta bilateral investment treaty in the banking services sector.
  • The Republic of Côte d’Ivoire in an ICSID arbitration commenced by Wise Solutions CDI, SA arising out of a dispute relating to a concession contract for waste management services in Abidjan.
  • Georgia in an UNCITRAL arbitration brought by a group of investors under the US-Georgia bilateral investment treaty relating to a real estate project.
  • Georgia in an ICSID arbitration commenced by Mr. Nasib Hasanov, under the Georgia-Azerbaijan bilateral investment treaty, in connection with an investment in a Georgian internet service provider that owns a 1,200 km submarine, fiber-optic cable across the Black Sea, connecting Europe and the South Caucasus.
  • The Arab Republic of Egypt in an ICSID arbitration commenced by H&H Enterprises Investments, Inc. under the US-Egypt bilateral investment treaty relating to the development of a tourist resort.
  • The Arab Republic of Egypt in an ICSID arbitration commenced by Unión Fenosa Gas under the Spain-Egypt bilateral investment treaty relating to an investment in an LNG plant and ensuing annulment proceedings.
  • The Republic of Iraq in an ICC arbitration against the Republic of Turkey for breaches of intergovernmental agreements governing the operation of transnational oil pipelines and related facilities.
  • The Republic of Iraq in a VIAC arbitration concerning claims under financial arrangements in violation of the financial sanctions imposed by the UN Security Council on the Saddam Hussein regime.
  • OJSC Tatneft in an UNCITRAL arbitration brought against Ukraine under the Russia-Ukraine bilateral investment treaty relating to an investment in a refinery and ensuing annulment and enforcement proceedings.
  • The Republic of Tatarstan and its Ministry of Land Property Relations in an UNCITRAL arbitration against Ukraine under the Russia-Ukraine bilateral investment treaty relating to an investment in a refinery.
  • DP World in an ICSID arbitration against the Republic of Peru under a concession agreement for the development and operation of the South Pier of the Port of Callao and the UK-Peru bilateral investment treaty.
  • The Russian Federation in three parallel UNCITRAL arbitrations under the Energy Charter Treaty commenced by one Isle of Man and two Cypriot companies, in their capacities as former majority shareholders of Yukos Oil Company, and ensuing annulment proceedings before the Hague District Court.
  • The Russian Federation in an SCC arbitration under the UK-Soviet bilateral investment treaty relating to Yukos Oil Company’s liquidation.
  • Électricité de France (EDF) in an ICC arbitration initiated by the Federal State of Baden-Württemberg, through a special purpose company, which had acquired EDF’s shareholding in the German energy company Energie Baden-Württemberg AG (EnBW).
  • OAO Gazprom in an UNCITRAL arbitration brought against the Republic of Lithuania under the Russia-Lithuania BIT concerning the forced divestiture of AB Lietuvos Dujos' natural gas transmission operations and assets.
  • The Republic of Slovenia in two Chamber and Grand Chamber proceedings before the European Court of Human Rights in disputes concerning liabilities arising out of the former Socialist Republic of Yugoslavia’s guarantee of foreign currency deposits.
  • E.T.I. Euro Telecom International N.V. in ICSID and UNCITRAL arbitrations against Bolivia under the Netherlands-Bolivia bilateral investment treaty in the telecommunication sector.
  • The Bank for International Settlements in proceedings before an arbitral tribunal established pursuant to Article XV of the Agreement signed at The Hague on January 20, 1930 commenced by the Bank’s former private shareholders seeking additional compensation for the mandatory redemption of their shares.

Includes matters handled prior to joining Dechert.

  • University of Vienna, Master in Law, 1990
  • University of Vienna, Doctor iuris (Dr. iur.), 1992
  • University of Vienna, Venia legendi et docendi (habilitation), 1997
  • Paris
  • English
  • German
  • French
  • Vienna Criminal District Court
  • Vienna Commercial Court
  • Vienna District Court
  • Court of Arbitration of the Singapore International Arbitration Centre
  • Board of the Vienna International Arbitral Centre
  • Energy Charter Treaty Legal Advisory Task Force
  • Board of Trustees of the Foundation of International Arbitration Advocay
  • American Society of International Law
  • European Society of International Law
  • German Society of International Law
  • International Law Association
Speaking Engagements
  • Course on the SIAC Investor-State Dispute Settlement – the National University of Singapore (September 26, 2020)
  • Course on the SIAC Investor-State Dispute Settlement – Fudan University (November 1, 2020)
  • Advanced Research Seminar on International Responsibility – the University of Vienna (Winter 2020)
  • International Investment Law and Human Rights – National and Kapodistrian University of Athens, ELSA Summar Law School Webinar (August 2020)
  • Perspectives and Insights on Current Issues and Developments in International Arbitration – SIAC India Webinar (May 2020)
  • Clear Path or Jungle in Commercial Arbitrators’ Conflicts of Interest? – ASA Annual Conference 2020, Zurich (February 2020)
  • The Boundaries of Investment Arbitration: The Use of Trade and European Human Rights Law in Investor-State Disputes – WilmerHale, London (December, 2019)
  • Evolution of Investment Law in Treaty Making and Arbitral Practice – 10 Year Anniversary Conference of the International Investment Law Centre Cologne, Cologne (May 2019)
  • 30 Years of Investment Treaty Arbitration: An Engine for the Development of General International Law for Good and for Bad – MIDS Lecture, Geneva Center for International Dispute Settlement, Geneva (May 2019)
  • Transforming Institutions in Investor-State Dispute Settlement – Harvard Law School (March 2018)
  • Denial of Benefits: When – How – Effects? – 7th Investment Treaty Arbitration Conference, Prague (October 2017)
  • Parallel Proceedings in Investment Arbitration – 2nd UNCITRAL Asia Pacific Judicial Conference on International Law, Hong Kong (October 2017)
  • Forging the Path in Asia: The Draft SIAC Rules on Investment Arbitration – SIAC Congress, Singapore (May 2016)
  • The Reaction to Contemporary Jurisprudence – Time to Move from Hegemony and Fragementation to Harmonization? – GAR Live BITs Conference, Washington D.C. (April 2015)
  • Are Contracting Parties Successfully Clawing Back Investment Treaty Protections? – GAR Live Conference, Frankfurt (June 2014)
  • Utilization of Investment Treaties to Compel or Effectively Reverse the Enforcement of Commercial Awards: Can Investment Treaty Protections Provide a Second Bite at the Enforcement Apple? – Columbia Arbitration Day, New York, NY (March 2014)
  • Legitimate Expectations: The Litigation of Public Law Concepts in Investor-State Arbitration – Practical and Theoretical Considerations – Twentieth Investment Treaty Forum Public Conference, British Institute of International and Comparative Law, London (May 2013)
  • Prospects for Reform of the New York Convention of June 10, 1958 – Seminar on recognition and enforcement of arbitral awards, ICC International Court of Arbitration, UIA Arbitration Commission and ArbIt, Italian Forum for International Arbitration and ADR, Rome (September 2011)
  • European Civil Procedure and Arbitration – Vienna Arbitration Days, Vienna (Feburary 2012)
  • Corruption, Fraud, Illegality Issues in Investment Arbtration – “Como Espada y Escduo” – Yale Law School (April 2012)
  • Investment Treaty Arbitration from the Perspective of the Host State – Asian African Legal Consultative Organization, United Nations, New York, NY (November 2011)
  • Recent Trends of Investment Treaty Arbitration: Policy Implications Host States’ Perspectives – Seoul National University, Seoul (May 2009)