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Sub practice
Sub practice

Public International Law and Investment Treaty Disputes

Allen & Overy’s specialist Public International Law team acts for corporations, financial institutions, international organisations, governments and States in all aspects of contentious and non-contentious public international law matters, including investment disputes. 

Our market leading practice combines expertise in issues such as title to natural resources, state responsibility and succession, boundary disputes, investment treaty arbitration, trade law and sanctions.

A&O’s advisory work spans the full range of public international law issues, including:

  • drafting and negotiation of international treaties and conventions
  • investment protection measures
  • international sanctions regimes
  • privileges of international organisations and state immunity
  • recognition of states and state succession
  • human rights
  • trade law

On the contentious side, we have a pre-eminent investment treaty arbitration practice acting for investors and sovereign States. We have advised on more than 70 investment treaty disputes and a number of ICSID annulment proceedings, and are one of only a handful of law firms to have experience of WTO disputes.

We advise on State-to-State disputes arising under public international law and team members have acted as counsel before international courts and special tribunals, and have also advised States on out-of-court strategies for dispute resolution.

Our experience includes advising:

  • A State on its negotiation with the European Union in relation to a comprehensive free trade agreement.
  • A Middle Eastern State on the potential reform of its investment treaties. 
  • The investment arm of a Middle Eastern State in relation to a draft bilateral investment treaty being negotiated with a South American State, and on how best to structure new investment acquisitions in that State.
  • Over 30 different international investors, in 12 separate ECT claims (all claims bar one brought at ICSID) against the Kingdom of Spain. The claims relate to investments made in the Spanish renewable energy sector, and retrospective changes by Spain to the regulatory framework. These cases include the first-ever collective, or aggregated, claim brought under the ECT. We have so far achieved significant damages awards for our clients in six of these arbitrations, with others still pending.
  • The Islamic Republic of Pakistan in two related claims, brought under the UNCITRAL Rules, arising from alleged interference in gas import operations at a port terminal. The Tribunal dismissed the nearly USD600m claims in their entirety and ordered the claimants to pay nearly 90% of Pakistan’s costs. We successfully defeated challenges to the Award, made by the claimants, in the English courts.

Awards and achievements

  1. Tier One, Public International Law, Legal 500 UK 2022
  2. Band 1, Dispute Resolution, Global: Multi-Jurisdictional, Chambers Global 2022
  3. International Arbitration Firm of the Year, Benchmark Litigation Asia-Pacific Awards 2020
  4. Leading firm (top tier) ranking in the “Leaders League” table for International Arbitration (Spain) 2022
  5. 24 lawyers ranked in Who's Who Legal: Arbitration 2024, including one Global Elite Thought Leader and nine Thought Leaders

Recognition

News and insights

Lights reflecting on the windows of modern skyscrapers

Publications: 20 December 2023

The implication of the Foreign State Immunity Law on cross-border disputes in the PRC and Hong Kong

The long-standing practice to adopt the principle of absolute foreign state immunity by the People’s Republic of China (the PRC) and Hong Kong is coming to an end as the PRC’s Foreign State Immunity…

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Big Ben

Publications: 04 October 2023

The UK’s Foreign Influence Registration Scheme: further enhancing the UK’s national security toolbox

Last September, the UK Government introduced the Foreign Influence Registration Scheme (FIRS) by way of amendment to the National Security Bill (the Bill). 

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High rise buildings

Publications: 02 May 2023

United Nations General Assembly seeks historic climate change opinion from International Court of Justice

On March 29, 2023, the United Nations General Assembly passed Resolution 77/276, marking a watershed moment in the global fight against climate change. The resolution requests an advisory opinion from…

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Sun shining on skyscraper

Publications: 26 April 2023

The U.S. Eleventh Circuit Court of Appeals en banc overturns Industrial Risk and INPROSTA

Last year, we wrote about precedent in the U.S. Court of Appeals for the Eleventh Circuit holding that international arbitration awards issued in the U.S. and encompassed by the New York Convention…

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