Nicolas Gillen

Dr Nicolas Gillen

Senior Associate

Nicolas is a senior finance litigator who advises banks and corporate clients on complex and high-stakes disputes.

He has a strong track record of representing clients in court proceedings and arbitrations involving securities transactions, loan contracts, banking restructuring measures and tax-driven transactions.

He combines strategic thinking, diligence and academic excellence to achieve optimal outcomes for his clients. He is also well-versed in international civil procedure and cross-border litigation. Nicolas is calm and confident in the courtroom and has successfully handled numerous cases before various courts.


Representative matters

An international financial group in relation to civil litigation issues relating to cum/ex-trades.

A major trading bank against claims resulting from the changed legal view of the finance administration on stock loans (cum/cum-transactions).

A bank against damages claims from the purchaser of an estate that had been mortgaged to the bank.

A large real estate company as lead counsel in the defence against post-M&A claims in the U.S., Germany and Scandinavia.



Pro bono

Advising a human rights organization on criminal accountability for war crimes committed in Syria.

Supporting an international NGO in relation to applications of vulnerable Afghan citizens under the German Federal Admission Programme for Afghanistan (Bundesaufnahmeprogramm für Afghanistan).

Published Work

  • Gillen, N. (2023) "Haftung für die unentgeltliche Anlage von Fremdvermögen am Beispiel von Kryptowährungen", Anmerkung zu OLG Frankfurt a.M., Urteil vom 20.06.2023 – 13 U 82/22, jurisPR-BKR 6/2023 Anm. 3 (Co-Author with Leif Schubert)
  • Gillen, N. (2022) "Zur Einordnung eines Zins-Swap-Vertrages als Finanzierungsberatungsvertrag sowie zum Umfang der daraus resultierenden Beratungspflichten", Anmerkung zu OLG Frankfurt a. M., Urteil vom 02.02.2022 - 17 U 19/20, EWiR 2022, p. 323
  • Gillen, N. (2021) "Kryptowährungen in der Zwangsvollstreckung", Anmerkung zu OLG Düsseldorf, Beschluss vom 19.01.2021, I-7 W 44/20: jurisPR-BKR 9/2021 Anm. 4 (Co-Author with Leif Schubert)
  • Gillen, N. (2020) "Immunitätsverständnis beim Umtausch von Staatsanleihen", Anmerkung zu BVerfG, Beschluss vom 06.05.2020 - 2 BvR 331/18: EWiR 2020, p. 749 (Co-Author with Holger Jacobs)
An outstanding senior associate whose knowledge, thoughtfulness and calm approach in the face of great pressure continues to impress us
Legal 500, 2024



Rechtsanwalt, Germany, 2014


Second State Exam, Law, Germany 2014

Doctor iur., Law, Albert Ludwigs University Freiburg im Breisgau, Germany, 2012

First State Exam, Law, Germany, 2009


German, English, Rumanian, French
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.