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Matej Kosalko

Senior Associate

Matej is a dual qualified (English and Slovak law) associate specialising in commercial and investment treaty arbitration as well as litigation. 

Matej has represented clients from various sectors in arbitration and litigation proceedings including energy, infrastructure, real estate, retail, finance, and technology and media.

Matej has represented clients in commercial and investment arbitration proceedings seated in both civil and common law jurisdictions (e.g. London or Vienna) and under ICC, LCIA, VIAC and ICSID arbitration rules.

He has extensive experience in complex construction disputes in PPP projects, and under FIDIC and other EPC forms of contracts. Matej frequently appears on behalf of the clients before adjudication boards (DABs), state courts and arbitral tribunals. He acted for contractors and employers in major construction projects in the Slovak Republic but also abroad.


Pro bono

Represented individual victims of a violation of their rights of privacy and non-discrimination, as set out in the European Convention on Human Rights, in cooperation with international public interest law organization working to combat racism.

Published Work

  • “Has Slovakia become an arbitration-friendly jurisdiction?”, LEXOLOGY, 2019
  • “Act of State doctrine applies in arbitration”, co-authored with L. Raimanova, JD Supra, 2018
  • “Awards on Costs in Investment Arbitration”, speaking at Comenius University, Bratislava, Slovak Republic, 2018
  • “(In)Genuinely Foreign Investment: A Survey of Nationality Requirements in Investment Dispute”, European Investment Law and Arbitration Review, Volume 3: Issue 1, 2018 (Won EILA essay competition of 2018.)

Speaking Engagements

  • Richard Dewitt Arbitration Conference, Comenius University, Bratislava, 26/04/2018
  • Riga 11th VIS Pre-Moot Conference, University of Latvia, 09/03/2017

Leadership Positions And Professional Affiliations

  • Fellow, Chartered Institute of Arbitrators Advokat
  • Slovak Bar Association Solicitor of Senior Courts of England and Wales, The Law Society
Matej focuses on FIDIC contracts in the context of Slovak construction law. We appreciate his personal involvement and high level of knowledge in construction.
The Legal 500 2022



Admitted as solicitor, England and Wales, 2018

Fellow of the Chartered Institute of Arbitrators, 2017

Admitted as attorney, Slovak Bar Association, 2014


LL.M. in International Business Law, Central European University, accredited by the University of the State of New York, 2010

Diploma in Higher Education in an Introduction to English Law and the Law of the EU, University of Cambridge, 2010

Matej Bel University, Law Faculty, Slovak Republic, 2009

A&O Shearman was formed on May 1, 2024 by the combination of Shearman & Sterling LLP and Allen & Overy LLP and their respective affiliates (the legacy firms). Any matters referred to above may include matters undertaken by one or more of the legacy firms rather than A&O Shearman.