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Marie Stoyanov



Stoyanov Marie
Marie Stoyanov



Paris-based partner Marie specialises in commercial and investment treaty arbitration. She has advised and represented clients in arbitrations throughout the world, both ad hoc and under all the major institutional rules, including the ICC, LCIA and ICSID Rules in which she has particular expertise.

Marie has substantial experience across all market sectors but her practice focuses particularly on infrastructure, energy, and natural resource disputes, with expertise in disputes arising across the African continent.

With clients that include both international investors and sovereign States, Marie regularly appears as advocate before renowned international tribunals arguing extremely complex cases, often with hundreds of millions of dollars at stake. Marie also sits as an arbitrator herself and has written and spoken regularly about international investment and arbitration.

After graduating from ESSEC, Marie studied law and was admitted to the Paris bar in 2003. As a French qualified lawyer, she is naturally used to working in all civil-law environments, in particular those whose law is directly derived from French law (e.g. Algerian law, Egyptian law, Moroccan law, UAE law).

In addition, Marie has also advised various clients on how best to structure their investment in Africa, Eastern Europe and Asia, in order to take advantage of protections offered by investment treaties and foreign investment laws.

A member of the Executive Board of the European Federation for Investment Law and Arbitration (EFILA), Marie is also an Advisory Board member of the publication Investment Claims, which is published by Oxford University Press.

Marie is a recognised practitioner by « Best Lawyers » since 2020 in Arbitration and Mediation.

Marie was awarded the 'Leading Commercial & Investment Arbitrator of the Year 2019' for Acquisition International Magazine - France.

"Marie Stoyanov is remarkably intelligent, sharp and professionally competent with wideranging expertise."
Legal 500 EMEA 2021 - France (Dispute resolution: International arbitration)

"Next Generation Partner"

Band 4
Chambers Global/Europe 2020 - France (International Arbitration)

Marie Stoyanov of Allen & Overy LLP regularly advises on investment treaty arbitrations, acting for both the states and private investors. Her practice includes handling cases brought under the Energy Charter Treaty. Clients comment: "She is very accessible and has a real commitment to service."
Chambers Global/Europe 2020 - France (International Arbitration)

* * - Arbitrage international 
ODA 2019 - France“

She is "diligent and impressive in terms of her knowledge of the subject and of the proceedings." 
Chambers Global 2018 - France (Dispute Resolution: International Arbitration)

"Next Generation Lawyer"
Legal 500 2017 - France (Dispute Resolution/International Arbitration)

Marie was awarded the “Star of Tomorrow” distinction for International Arbitration by French newspaper Les Echos, Marie is described by Chambers & Partners as having “particular focus on investment treaty and related disputes”, in which context she is “very sharp in understanding and reaching the crux of even the most complicated issues” 
Chambers 2017 - France (Dispute Resolution: International Arbitration)

"Marie Stoyanov is 'very sharp in understanding and reaching the crux of even the most complicated issues'." 
Chambers 2017 - France (Dispute Resolution: International Arbitration)

"Marie Stoyanov is described as 'an outstanding, talented lawyer'." 
Chambers 2016 - France (Dispute Resolution: International Arbitration)

News & insights

Sun reflecting off high rise windows

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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Climate ESG prudential regulation and risk management

Publications: 05 JULY 2021

Country and sustainability risk mitigation: a briefing for energy and mining investors

The transition of the global economy to align with the Paris Agreement aims and the UN Sustainable Development Goals is presenting many opportunities for energy and mining investors. However, it is…

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France urges the EU to withdraw from the ECT

Publications: 03 MARCH 2021

France urges the EU to withdraw from the ECT

The EU should express its readiness to withdraw from the Energy Charter Treaty, France says in a letter to the European Commission.

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Publications: 25 NOVEMBER 2020

France considers retroactive solar tariffs cuts, at the risk of facing investment-treaty claims

On 13 November 2020, the French National Assembly (Assemblée nationale) approved an amendment to the draft Finance Law (Projet de loi de finances) for 2021, which seeks to implement a “targeted…

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Allen & Overy LLP
52 avenue Hoche
75008 Paris

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PGD, International Arbitration, Queen Mary University of London, 2003

ESSEC Business School, 1997

Published work

  • Sentence Micula : un tribunal condamne la Roumanie à payer 250 millions de dollars,, April 2014, written with Sebastiano Nessi
  • Enjeux et portée de la sentence Micula, Capital Finance, March 2014, written with Sebastiano Nessi
  • Interview - « Dès qu’un pays devient exportateur de capitaux, il est enclin à se porter vers l’arbitrage », Capital Finance, n° 1125, october 2013
  • Third-Party Funding in International Arbitration : Is it time for Some Soft Rules?, International Arbitration Review, June 2015, written with Olga Owczarek
  • Multiparty Proceedings and Mass Claims, The Investment Treaty Arbitration Review, April 2016, written with Jeffrey Sullivan and Lucia Raimanova
  • Procedural interplay between investment arbitration and criminal proceedings in the context of corruption allegations, b-Arbitra, 2018, written with Werner Eyskens, Valentin Bourgeois and Michaël Fernandez-Bertier