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Grzegorz Kostrzewa


Grzegorz (Greg) specialises in commercial disputes, regulatory disputes, white-collar crime and investigations.

Greg has been providing legal advice to high-profile Polish and international entrepreneurs since 2006. He has represented clients from various sectors in hundreds of court proceedings – before common, administrative and arbitration courts – as well as in preparatory and explanatory proceedings before law enforcement agencies and regulatory authorities. He has also assisted in a number of internal investigations and dawn raids. Additionally, he demonstrates expertise in sports matters, particularly in disciplinary and arbitration proceedings.

Before joining A&O, he worked in the litigation departments of renowned international and Polish law firms. Greg has been repeatedly recognised by Legal 500 in the fields of dispute resolution and white-collar crime.


Representative matters

An energy company on a EUR1.5bn dispute concerning the reckoning of costs associated with the construction of a power plant in Poland. (previous firm experience).

A telecommunications company on EUR650m damage-related criminal proceedings resulting from irregularities in public procurement proceedings to the detriment of this company. (previous firm experience).

A retail company on a EUR100m arbitration post-M&A dispute against an accounting company resulting from the non-performance of its obligations towards the parties of the M&A contract. (previous firm experience).

An oil company on a USD5m arbitration dispute against a Russian company resulting from contaminated crude oil deliveries. (previous firm experience).

Adam Kowalczyk and Grzegorz Kostrzewa’s involvement and cooperation is highly-rated and they are standout partners
Legal 500 EMEA, 2023
Grzegorz Kostrzewa and Adam Kowalczyk are excellent lawyers, great cooperation, contact, know-how of business
Legal 500 EMEA, 2022



Warsaw Bar Association, 2013 (Advocate)


MA, Faculty of Law and Administration, University of Warsaw, 2008
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.