Claudia Annacker

Dr. Claudia Annacker is an international arbitrator and counsel specializing in international arbitration and public international law, with a particular focus on investor-State disputes, inter-State disputes, disputes involving international organizations and human rights cases. She has more than 30 years of experience in international dispute settlement and has acted as arbitrator and counsel in more than 50 investment arbitrations, as well as in numerous commercial arbitrations. Before establishing her own practice in 2024, she was a partner at Cleary Gottlieb and Dechert.

Dr. Annacker is a member of several arbitrator panels, including the ICSID Panel of Arbitrators and the SIAC Panel of Arbitrators. She serves on the World Bank Group Sanctions Board, the SIAC Court of Arbitration and the VIAC Board.

She is also an adjunct professor at the University of Vienna, where she teaches advanced research seminars in international responsibility and international dispute settlement and supervises PhD theses. In addition, she regularly lectures at other leading universities. She has published widely in the fields of international arbitration and public international law.

Dr. Annacker holds a PhD and habilitation in public international law from the University of Vienna.

Books and Book Chapters

- Articles 13 to 15 of the International Law Commission’s Articles on Responsibility of States for Internationally Wrongful Acts, in: Commentary on General International Law in International Investment Law, M. Waibel and A. Kulick eds., Oxford Commentaries on International Law Series (2024).

- Evolution of Investment Law in Treaty Making and Arbitral Practice: Comments from Counsel’s Perspective, in: Evolution, Evaluation and Future Developments in International Investment Law – Proceedings of the 10 Year Anniversary Conference of the International Investment Law Centre Cologne, St. Hobe and J. Scheu eds. (2021).

- Issues relating to Challenging and Enforcing Arbitration Awards – ICSID Awards, in: The Guide to Challenging and Enforcing Arbitration Awards, J. William Rowley, Emmanuel Gaillard, and Gordon E. Kaiser eds. (2019).

- Der fehlerhafte Rechtsakt im Geimeinschafts- und Unionsrecht (Defective Legal Acts in EU Law) (1999), Vienna/New York.

- Die Durchsetzung von erga omnes Verpflichtungen vor dem Internationalen Gerichtshof (The Enforcement of Erga Omnes Obligations before the International Court of Justice) (1994) Hamburg.

Articles

- Operation and Termination of Sunset Clauses in Bilateral Investment Treaties, NLS Business Law Review (2024).

- Fragmentation and Integration in International Investment Law: Plus Ça Change, ICSID Review – Foreign Investment Law Journal (2023).

- 2021 Vienna Investment Arbitration Rules, Austrian Yearbook on International Arbitration (2022).

 Conflicts of Interest under the SIAC Rules, Clear Path or Jungle in Commercial Arbitrators’ Conflict of Interests, ASA Special Series, Vol. 48 (2021).

- Role of Investor’s Legitimate Expectations’ In Defense of Investment Treaty Claims, Yearbook on International Investment Law & Policy 2013-2014 (2015).

- Investment Treaty Arbitration as a Tool to ‘Enforce’ Arbitral Awards?, The European, Middle Eastern and African Arbitration Review (2015).

- Protection of Sovereign Wealth (book review), ICSID Review – Foreign Investment Journal (2014).

- Protection and Admission of Sovereign Investment under Investment Treaties, Chinese Journal of International Law, Vol. 10 (2011).