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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 2019
  2. Band 1, Dispute Resolution, Global-wide, Chambers Global 2019
  3. International Arbitration Firm of the Year, Benchmark Litigation Asia-Pacific Awards 2019
  4. Best Arbitration Team of the Year in Spain and Portugal, 2019 

Recognition

News & insights

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Publications: 06 SEPTEMBER 2021

Intra-EU disputes cannot be arbitrated under the Energy Charter Treaty, says the Court of Justice of the European Union

On 2 September 2021, the Grand Chamber of the Court of Justice of the European Union (the Court) delivered its judgment in Case C-741/19, Republic of Moldova v Komstroy LLC, finding that the…

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Classical Greek Columns in a Bank building

Publications: 09 AUGUST 2021

Nestle v Doe: U.S. Supreme Court further defines scope of Alien Tort Statute (ATS)

Nestle USA v. Doe: U.S. Supreme Court confirms Nestle and Cargill cannot be sued in the US for alleged aiding and abetting of forced labour overseas.

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Sun peering behind modern skyscrapers on the skyline

Publications: 29 JULY 2021

Lukas Rengier and Fabian Kolf contribute chapters to Lexology's Private Antitrust Litigation 2022

Lukas Rengier and Fabian Kolf, members of our global antitrust team based in Hamburg, have contributed two chapters to the latest (2022) edition of Lexology Getting The Deal Through's Private…

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Publications: 06 JULY 2021

Vienna International Arbitral Centre launches new investment arbitration and mediation rules

With effect from 1 July 2021, the Vienna International Arbitral Centre (the VIAC) has new specialised VIAC Rules of Investment Arbitration (Vienna Investment Arbitration Rules) and the VIAC Rules of…

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