Legal 500, Dispute Resolution : Leading Partner
Me Nicolas Thieltgen
Managing Partner
Senior Partner
Avocat à la Cour
“For a lawyer, complete mastery of the law is both a given and an absolute requirement: in this respect, only excellence will do. Yet what truly distinguishes a good lawyer goes beyond legal expertise. It also lies in their human qualities, commitment, experience and ability to think differently. These qualities enable them to look beyond the terms of the question put to them, identify their client’s real need and provide the most appropriate, useful and well-judged response.”
16-18 Boulevard Emmanuel Servais
L-2535 Luxembourg
Bar admission
Luxembourg, 26 avril 2001
Languages
Français / Anglais
Expertises
Alternative Dispute Resolution & Arbitration
Arbitration
Banking & Finance
Regulatory, Transactions
Corporate, Commercial & M&A
Commercial Advisory, Maritime & Transport law
Dispute Resolution
Administrative law litigation, Banking & Finance Litigation, Corporate Litigation & Shareholders' Disputes, Court of Cassation Proceedings, Enforcement, Family law and inheritance litigation, Financial & Criminal Business Law, General commercial & civil litigation, Real estate litigation, Tax Litigation
ESG & Sustainability
Insurance & Liability
Intellectual Property, IT & Data
Private Clients
Public & Administrative law
Administrative Law & Sectoral Regulation, Public Procurement
Real Estate & Construction
Construction law
Restructuring & Insolvency
Insolvency, Interim administration, Liquidation, Restructuring
Sanctions, AML/CFT & Compliance
Sport Law
Education
Graduate of the Faculty of Law at the University of Leuven (Belgium)
Rankings
Chambers & Partners, Dispute Resolution : Band 2
Chambers & Partners, Banking & Finance: Regulatory : Band 3
Membership
-
ALJB – The Luxembourg Banking and Financial Law Association
President
-
International Bar Association
Member
-
International Association of Young Lawyers (AIJA)
Honorary Secretary-General and former Vice-President of the Banking, Finance and Capital Markets Commission
-
Legalmondo
Member
- Elected member of the Luxembourg Bar Council (2018–2020)
Selected Experience
My practice primarily focuses on domestic and international business litigation. I act in complex, sensitive and high-stakes commercial disputes, particularly in relation to shareholder conflicts, corporate governance, contractual liability and disputes arising from financial transactions.
I advise and represent clients at every stage of a dispute, from risk assessment and strategy development through to the conduct of proceedings before state courts and arbitral tribunals. I act in domestic and international arbitrations, both as counsel to the parties and, on occasion, as arbitrator. I regularly handle matters involving significant financial exposure, complex legal issues and substantial strategic or cross-border dimensions.
I also have extensive experience in multi-jurisdictional proceedings, including complex debt recovery, interim and protective measures, and the recognition and enforcement of foreign judgments and awards.
Alongside my dispute resolution practice, I advise clients on banking and finance law, including regulatory matters, financing transactions and related disputes. I also act in white-collar criminal proceedings concerning the financial sector.
Publications and Editorial Responsibilities
N. Thieltgen, « Chronique annuelle de jurisprudence de droit bancaire et financier luxembourgeois » (“Annual Review of Luxembourg Banking and Financial Law Case Law”), Bulletin Droit et Banque, since 2008.
N. Thieltgen, M. Bena and P. Sylvestre, « Brucher Thieltgen & Partners : le contentieux à l’ère de l’exigence » (“Brucher Thieltgen & Partners: Litigation in an Era of High Standards”), Le Figaro, Portraits d’entreprises, May 2026.
N. Thieltgen and A.-M. Ka, « Entre compétitivité et Europe : les lignes de force à anticiper pour 2026 » (“Between Competitiveness and Europe: Key Trends to Anticipate for 2026”), Paperjam, December 2025.
N. Thieltgen, « Une expertise locale et une vision internationale » (“Local Expertise and an International Vision”), Inspir’, MEDEF, 2025.
N. Thieltgen and A.-M. Ka, « Les défis contemporains du droit bancaire et financier : perspectives et solutions » (“Contemporary Challenges in Banking and Financial Law: Perspectives and Solutions”), Revue AFJE, 2025.
N. Thieltgen, « “In the Mood for Law” : le CLO et l’avocat » (“In the Mood for Law: The CLO and the Lawyer”), Paperjam Extra, July 2025.
N. Thieltgen, « Comment prévenir et comment résoudre les conflits au sein des sociétés » (“How to Prevent and Resolve Corporate Disputes”), Paperjam, November 2024.
N. Thieltgen, « Les taux d’intérêt négatifs » (“Negative Interest Rates”), Bulletin Droit et Banque, No. 62, June 2018.
N. Thieltgen, « Le régime juridique des intérêts dans la perspective du banquier luxembourgeois » (“The Legal Framework Governing Interest from the Perspective of a Luxembourg Banker”), Droit bancaire et financier au Luxembourg, 2014.
N. Thieltgen, « Les pouvoirs de police des autorités communales en droit luxembourgeois » (“The Police Powers of Municipal Authorities under Luxembourg Law”), Droit administratif et fiscal – 10 années de juridictions administratives, 2007.
N. Thieltgen, « Le consommateur et sa banque – L’évolution depuis 1993 de la protection juridique du consommateur dans le domaine bancaire et financier » (“Consumers and Their Banks – Developments in the Legal Protection of Consumers in Banking and Finance since 1993”), Droit bancaire et financier au Luxembourg, 2004.
Conferences and Educational Engagements
« Les conflits d’actionnaires – Table ronde sur les procédures » (“Shareholder Disputes – Round Table on Proceedings”), symposium on shareholder disputes, Faculty of Law, Economics and Management of the University of Nancy, March 2026, Nancy, with R. Aydogdu, M.-A. Bibalou Mossodji, C. Karsenti and J.-B. Hacquet.
“Fundamentals and Sources of Luxembourg Financial Law”, ALJB Newcomers’ Conference, 26 November 2025, Luxembourg.
« Panorama de la jurisprudence luxembourgeoise en matière de prêt (2015-2025) – Quels enseignements pour la place financière ? » (“Overview of Luxembourg Case Law on Loans (2015-2025) – What Lessons for the Financial Centre?”), ALJB, 19 September 2025.
« Le juge des référés est-il l’arbitre ultime des conflits au sein des sociétés ? » (“Is the Interim Relief Judge the Ultimate Arbiter of Corporate Disputes?”), Meetincs, 3 June 2025, Luxembourg.
« Les procédures unilatérales sur la base de l’article 66 du Nouveau Code de procédure civile » (“Ex Parte Proceedings under Article 66 of the New Code of Civil Procedure”), Luxembourg Young Bar Conference, 28 November 2023, with P. Wadlé and H. De Ron.
« Le contentieux au sein des sociétés : jurisprudences récentes » (“Corporate Disputes: Recent Case Law”), Luxembourg Young Bar Conference, 19 April 2022, Luxembourg, with A. Morocutti and T. Kaufmann.
« Le secret d’affaires dans le secteur bancaire et financier au Luxembourg : principes et enjeux au travers du cas fictif “Zauberflöte” » (“Trade Secrets in Luxembourg’s Banking and Financial Sector: Principles and Challenges through the Fictional ‘Zauberflöte’ Case”), ALJB Web’midi, March 2021, Luxembourg.
« L’administrateur provisoire de sociétés en droit luxembourgeois » (“The Interim Director of Companies under Luxembourg Law”), Luxembourg Young Bar Conference, 20 June 2018, Luxembourg, with F. Poncin.
“The Colorful Bouquet of Cross-Border Reorganization Possibilities”, AIJA, 20 October 2017.
“Roles and Responsibilities of Bank Board Members”, Luxembourg Institute of Directors, 1 October 2014, with A.-M. Nicolas.
Podcasts and Audiovisual Content
N. Thieltgen and F. Gilliers, B. Desjardins, “Mastering the Rules” podcast on searches, June 2025.
N. Thieltgen, M. Bena, N. Bernardy, A.-M. Ka and P. Sylvestre, “Mastering the Rules” podcast on corporate disputes, Paperjam, 2024.
Legal Popularisation and Social Media
“Pénal Express”, a Legal Design series on white-collar crime, published on LinkedIn.
“Business Tech’ & Privacy”, a Legal Design series on intellectual property, information technology and data protection law, published on LinkedIn.