Mergen specializes in complex business litigation and arbitration, in particular cases with an international or cross-border dimension. He has conducted numerous legal proceedings for his clients, including corporate and commercial disputes, the recognition and enforcement of foreign judgements and arbitration awards in Russian courts.

Mergen successfully represented ROSTEC in the defense of the attempts of Siemens AG to contest the delivery of gas turbines; represented Agrobusiness Group in respect of more than $1.5-mln claim brought by a Russian subsidiary of Sucres & Denrées; represented SAP CIS in different proceedings in Russian courts; coordinated the defense of ARMZ Uranium Holding Co, successfully opposing an attempt by the plaintiffs to obtain an order validating service of a statement of claim abroad in contravention of the Hague Convention on Service, effectively ending a $300-mln claim.

In addition to his work with clients, Mergen is lecturer in law in the International Business Transaction course at the Lomonosov Moscow State University Law Faculty and the HSE Faculty of Law. He is also an author of two books dedicated to sanctions issues: Economic Sanctions in the Law of the US, EU and Russia (published in 2016) and Economic Sanctions Against Russia: Legal Challenges and Perspectives (published in 2018).

In 2019, Best Lawyers recognized Mergen among leading dispute resolution lawyers in Russia. Kommersant ranking recommends Mergen for his work related to Russia’s transport industry.


Mergen joined the firm in 2015. He worked as a Partner at Egorov Kryazhevskikh & Partners, head of project at ARMZ Uranium Holding / TENEX and Head of Corporate Law Division / Associate at the Resource division of SEVERSTAL.


University of Pennsylvania Law School (LL.M. 2015)

University of Pennsylvania, Wharton's Aresty Institute of Executive Education (WBLC 2015)

Lomonosov Moscow State University (Ph.D. in Law 2012; Diploma in Law 2004)