Maria Kostytska est associée au sein du Arbitrage international du cabinet, spécialisée en arbitrage international et contentieux transfrontalier. Elle est inscrite aux barreaux de Paris, de New York, de District de Columbia, de Angleterre et du Pays de Galles en tant que barrister. Elle exerce la profession en cinq langues : l'anglais, le français, l'ukrainien, le russe et l'espagnol.
Maria intervient en qualité de conseil principal dans des arbitrages investisseur-État, État-État et commerciaux selon les règlements d’arbitrage du CIRDI, de la CNUDCI, de la CCI, de la LCIA et de la SCC. Elle siège également en tant qu’arbitre. Son expérience en arbitrage et en contentieux couvre de nombreux secteurs industriels, notamment le pétrole et le gaz, les énergies renouvelables, les services publics, les infrastructures, la banque, l’aviation et l’industrie manufacturière.
Maria a précédemment été membre de la Cour internationale d’arbitrage de la CCI à Paris pendant deux mandats consécutifs. Elle a été membre fondatrice du conseil du Georgian International Arbitration Centre (GIAC) à Tbilissi et figure sur les listes d’arbitres du Singapore International Arbitration Centre (SIAC), du Hong Kong International Arbitration Centre (HKIAC) et du Centro Internacional de Arbitraje de AmCham Perú.
Maria enseigne l'arbitrage d'investissement dans le cadre du Master en arbitrage et commerce international (MACI) de l'Université de Versailles.
Avant de rejoindre le cabinet, Maria a exercé les fonctions de responsable du département arbitrage au bureau parisien d’un autre cabinet d’avocats international.
- Citée par Chambers France comme leader de la pratique d’arbitrage international à Paris, 2025
- Classée par The Legal 500 ces dernières années
- Reconnue par Best Lawyers pour l’arbitrage international en France, 2020–2026
- Reconnue par Lawdragon 500 en tant que Leading Global Litigator à Paris, 2021, 2023–2025
- Reconnue par Who’s Who Legal: Arbitration pour l’arbitrage en France :
- Recommandée, 2024–2026
- Future Leader (Partners), 2022–2024
- Reconnue par Lexology Index: Arbitration en France, 2025 :
- Most Highly Regarded
- Global Elite Thought Leader
- Reconnue par GAR 100 comme leader de la pratique d’arbitrage international à Paris, notamment en 2024
- Citée par Décideurs (Leaders League) au sein du département Contentieux–Arbitrage à Paris, « forte notoriété », 2025
- L’équipe d’arbitrage international de Paris a remporté le Palmarès des Avocats – Trophée Or en arbitrage international, 2024 ; Trophée Bronze, 2014–2016
Maria est membre des associations professionnelles suivantes :
- ICC Commission on Arbitration and ADR
- Institut de Droit des Affaires Internationales de la CCI
- ICC France
- ICC Ukraine, Board Member and Head of the Arbitration Commission
- ICC Ukraine ICC USCIB
- Comité Français de l’Arbitrage (CFA)
- Association Française de l’Arbitrage (AFA)
- NYSBA International Law Section
- IBA Litigation and International Arbitration Committees
- Ukrainian Bar Association (UBA) International Law and Energy Committees
- Ukrainian Arbitration Association (UAA), Board Member
- Club Español de Arbitraje - Capítulo Francés y MUJERES
Cuestiones medioambientales en el arbitraje de inversión en el sector minero in Latinoamérica, AmCham Perú Arbitration Forum (September 2025)
“Iron grip and soft touch: women in energy, mining and infrastructure in Latin America,” Paris Arbitration Week (April 2025)
“Boots on the ground and a gaze on the horizon: what Ukrainian businesses expect from international arbitration,” Paris Arbitration Week (April 2025)
“Reparations - war, frozen assets and political risks,” Asset Recovery CEE, Warsaw (April 2025)
GAR LIVE: Women in Arbitration, “Energy disputes arising out of the war in Ukraine,” Paris (December 2024)
“Recovery of losses caused by the war in Ukraine,” III Conference of Pravo.ua/Legal Practice, Kyiv (November 2024)
“New investments in energy and causes of energy disputes: past and future,” Solidarity Arbitration and Mediation Days, Warsaw (October 2024)
“The impact of military conflicts and sanctions on arbitration,” International Commercial Arbitration Court (ICAC) in Kyiv (October 2024)
“Best practices in the gathering, marshaling and weighing of evidence in international arbitration,” ArbCEE retreat,Dubrovnik (October 2024)
“Las tendencias en arbitraje de inversión en el sector de las energías renovables,” XV Conferencia de Arbitraje Internacional, AMCHAM Ecuador, Quito (September 2024)
“Las últimas tendencias de valoración de los daños y perjuicios en arbitrajes de inversiones,” conferencia Women in Arbitration del Instituto Peruano de Arbitraje, Arequipa (July 2024)
“Energy disputes arising in the current geopolitical context,” Baltic Arbitration Days, Riga (June 2024) and Moldova Arbitration Days, Chisinau (May 2024)
“Retos y oportunidades en la representación de Estados en litigios internacionales,” Club Español e Iberoamericanode Arbitraje, Geneva (March 2024)
“Energy trends and disputes–in the current geopolitical and energy-transition context,” Paris Arbitration Week, Paris (March 2024)
“Ukraine - the rebuild and reparations,” Paris Arbitration Week, Paris (March 2024)
“International energy disputes after the invasion of Ukraine: can it handle the flux capacity?” ABA/ILS conference,Houston (February 2024)
“The impact of sanctions on international arbitration involving Russian, Belarusian and Ukrainian parties,” Solidarity Arbitration and Mediation Days, Warsaw (December 2024)
Curso de actualización “Arbitraje de inversiones,” ARBITRI e Pontifica Universidad Católica del Peru (PUCP) (December 2023)
“New challenges in enforcement of the arbitral awards,” GIAC Arbitration Days, Tbilisi (October 2024)
“Arbitraje, inversiones y la seguridad jurídica,” conferencia del Instituto Peruano de Arbitraje, Lima (September 2023)
“III Energy Law Conference” of the Ukrainian Bar Association, Warsaw (September 2023)
“Evolution or revolution: have we mastered international arbitration or do we need a new blueprint for the future?” Stockholm (August 2023)
“Arbitration in wartime,” Le Café des Arbitres, Paris (June 2023)
“Claims arising from the war in Ukraine: the role of the English jurisdiction,” London International Disputes Week, London (May 2023)
“The war in Ukraine: legal mechanisms for recovery of losses,” Paris Arbitration Week, Paris (March 2023)
“Due process paranoia in international arbitration,” as part of the panel on “Procedural efficiency in international arbitration,” International Commercial Arbitration Court (ICAC) in Kyiv (October 2019)
“Drafting enforceable awards,” ICC training, Kyiv (September 2019)
“Shareholder disputes in the CIS,” Paris Arbitration Week, Paris (April 2018)
“Jurisdiction over a sovereign in recognition and enforcement proceedings” and “Cross-jurisdictional cooperation between lawyers,” C5 conference on international disputes and assets recovery in the CIS, London (January 2018)
“2017 Rules: Changes Explained: Transparency,” ICC-ICC-Ukraine side event at the Kyiv Arbitration Days, Kiev (November 2017)
“Immunity from attachment and execution,” Baltic Arbitration Days, Riga (June 2017)
“How geopolitical tensions are shaping energy disputes,” ICDR oil and gas arbitration conference, Houston (April 2017)
“The U.S. and EU sanctions as a defense to non-performance of legal obligations,” CEA conference, Warsaw (May 2015)
“Legal remedies available to state-owned and private companies in connection with the situation in the Crimea and Eastern Ukraine,” Kyiv inter-ministerial seminar (December 2015)
“The Russian food import ban as a countermeasure to the U.S. and EU sanctions, and legal remedies to address it” Kyiv Arbitration Days (November 2015)
“Preparation of expert witnesses for examination: the do's and don'ts,” Swedish Arbitration Days, Stockholm (September 2014)
“How not to pay and get your money back . . . in international arbitration,” Winston client seminar, Paris (July 2013)
“Annulment and enforcement of arbitral awards in France, Switzerland and Tunisia,” Tunisian Ministry of Justice conference, Tunis (April 2013)
Nationality planning, treaty shopping and denial of benefits, ICC YAF oil and gas arbitration conference, Geneva (January 2013)
“Pathological arbitration clauses,” Winston client seminar, Paris (November 2012)
“Jurisdiction over investment and investor,” International Law Institute (ILI) seminar, Washington, D.C. (November 2012)
“Methodology of proof in international arbitration,” Ukrainian Ministry of Internal Affairs conference, Kyiv (November 2012)
“The use of valuation experts,” ABA conference, Moscow (September 2012)
“Damages in international arbitration,” ICC YAF conference and Winston client seminar, Paris (July 2012)
“Drafting of arbitration clauses and the binding effect of arbitration clauses on non-signatories,” ILI advanced arbitration seminar, Washington, D.C. (November 2011)
“Independence and impartiality of arbitrators,” ICC YAF conference, Prague (October 2011)
“Selection and appointment of arbitrators,” ICC PIDA seminar, Paris (October 2011)
“Applicable law in investment arbitration,” ILI seminar, Washington, D.C. (November 2010)
“Invoking human rights standards and precedents in investment arbitration,” ILA conference, the Hague (September 2010)
“Arbitration, litigation, and mediation of investor-State disputes,” UNCTAD and Ukrainian Ministry of Justice conference, Kiev (October 2009)
“Energy Disputes Arising from the Russian Invasion of Ukraine,” Transnational Dispute Management (TDM) ISSN1875-4120) April 2025
Cross-border enforcement of judgments against states, IBA jurisdiction-by-jurisdiction guide, United States chapter(2024)
Sovereign Immunity in France, LEXOLOGY (2023-2025)
Enforcement of Foreign Judgments in the United Kingdom, LEXOLOGY (2023-2025)
Jordan chapter, GAR Investment Treaty Arbitration Know-How (2015)
Book review of Gary Born’s “International Arbitration: Law and Practice,” Pravo Ukrainy (2013)
“Le contrôle post-arbitral de la sentence arbitrale internationale : Regards croisés en droit français, suisse ettunisien,” Pédone (2013)
“Declaratory Relief in International Arbitration,” Journal of International Arbitration, Kluwer (2012)
Fuchs v. Georgia, case digest, International Arbitration Case Law and GAR (2011)
Ukraine dispute resolution chapter, Getting the Deal Through and Transnational Dispute Management (TDM) (2006)
