Languages

English, Finnish, Swedish, French, German

Assistant

Laura Tyynismaa

Anna-Maria Tamminen

Partner Dispute Resolution

Languages

English, Finnish, Swedish, French, German

Assistant

Laura Tyynismaa

Anna-Maria specialises in dispute resolution, with a special focus on complex, international disputes and investigations. She currently represents parties in mediations, national and international arbitrations, administrative and civil litigations, and internal and regulatory investigations. She has also acted for clients before the ECJ and the Finnish and Swedish Supreme Courts. Since 2022, Anna-Maria has been in charge of Hannes Snellman’s sanctions and contentious ESG advice. As of April 2025, Anna-Maria acts as the managing partner of the firm.

Anna-Maria has experience in resolving disputes through negotiations, mediation, arbitration, and litigation. Her past work includes high-stakes commercial and investment cases requiring the application of general contract and commercial law (including franchise, agency, and shareholder disputes), tort law, international sales, post M&A, competition, and procurement law. She has worked with clients active in many industries, including technology, media & telecom, energy & infrastructure, real estate & construction, engineering & machinery, healthcare & life sciences, mobility, transportation & logistics, financial services & insurance, defence, consumer & retail and environment, natural resources & circular economy, and the public sector.


Anna-Maria has arbitrated cases under the ICC Rules, SCC Rules, FAI Rules, Vienna Rules, LCIA Rules, DIA Rules, UNCITRAL, and PCA Rules. Anna-Maria has additionally advised clients with regard to potential commercial and investment disputes, obtaining funding for disputes, seeking interim relief, and on the recognition, enforcement, and setting aside of arbitral awards in a variety of jurisdictions. Anna-Maria also acts as arbitrator in both international and domestic disputes. She has acted as sole arbitrator, co-arbitrator, and chairperson in over 30 international arbitrations under the ICC, SCC, FAI, DIA, and LCIA Rules with a value in dispute up to EUR 60 million. The cases have been subject to Swedish, Finnish, Danish, Cypriot, Swiss, German, English, and New York law.

She regularly publishes articles, presents at conferences, and lectures on dispute resolution topics. She is a member of the Board of the SCC Arbitration Institute and a member of the LCIA Court. In the years 2018–2024, she was a member of the ICC Court of arbitration representing Finland. She is also a past co-chair of the IBA Arbitration Committee’s ESG Subcommittee. Anna-Maria is trained in both common and civil law legal systems and is admitted to practice as an attorney in both Finland and the State of New York. Due to her training and work experience in Finland, Sweden, Austria, United Kingdom, and the United States, Anna-Maria has an in-depth understanding of both common and civil law legal systems.

Selected References

Hannes Snellman successfully represented Outokumpu Corporation in an international ICC arbitration between Fennovoima Oy and Rosatom entities where RAOS Project Oy sought to join Outokumpu in 2023. The Arbitral Tribunal accepted Outokumpu’s position denying jurisdiction over Outokumpu and ending the arbitration with respect to Outokumpu.

In January 2023, RAOS Project filed a request to join Outokumpu in existing ICC arbitration proceedings, which related to the termination of the engineering, procurement, and construction (EPC) contract between Fennovoima and RAOS Project regarding the Hanhikivi nuclear power plant. In February 2025, the Arbitral Tribunal confirmed that it did not have jurisdiction to adjudicate the claims brought by RAOS Project and JSC Rusatom Energy International (JSC REIN) against Outokumpu.

Contacts

Counsel to a Finnish listed corporation and its subsidiary in parallel multi-million arbitration proceedings under the FAI and SCC arbitration rules. The disputes subject to Finnish and Swedish law concerned supply agreements and parent company guarantees and involved aspects of EU-sanctions.

Contacts

Counsel to a Finnish company in a dispute concerning the interpretation of a service agreement against a Nordic logistics company where the dispute was settled in mediation.

Contacts

Counsel to a global corporation in parallel proceedings before the Helsinki District Court in relation to a license agreement and public procurement rules.

Contacts

Counsel to a Finnish company in Market Court proceedings subject to consumer protection law and energy regulation.

Contacts

Co-counsel to a major Finnish listed corporation in relation to a multibillion-euro investment treaty claim against the Russian Federation.

Contacts

Counsel to supplier of social services in a dispute against a public entity.

Contacts

Counsel to a Finnish listed company in its exit from Russia and related sanctions questions.

Contacts

Hannes Snellman acted as counsel in two precedential cases determining the invalidity of intra-EU arbitral awards in Sweden. Both cases concerned the application of EU law principles expressed in the European Court of Justice’s (ECJ) Achmea judgment and the case law following the judgment. Hannes Snellman successfully represented the Republic of Poland in the Swedish Supreme Court, where the arbitral awards were declared invalid on the basis of Section 33(2) of the Swedish Arbitration Act. We also successfully represented the Kingdom of Spain in the Svea Court of Appeal regarding an application to invalidate or set aside an intra-EU arbitral award under the Energy Charter Treaty.

Contacts

Parties:

Veolia Services Suomi Oy, Metsä Fibre

Transaction:

Veolia Services Suomi Oy’s project to build a crude methanol processing plant in connection with Metsä Fibre's Äänekoski bioproduct mill plant in Äänekoski

Deal Value:

Value not public

Role:

Counsel to Veolia Services Suomi Oy

Contacts

Counsel to a global corporation in set-aside proceedings before the Svea Court of Appeal.

Contacts

Counsel to a Finnish listed company in multiple parallel regulatory proceedings pending before different administrative courts in Finland.

Contacts

Counsel to a European State in the setting aside proceedings of an investment treaty award before the Svea Court of Appeal, Swedish Supreme Court and European Court of Justice involving questions of international law.

Contacts

Counsel to a Nordic company against a Central European counterpart in a multimillion-euro SCC arbitration and obtained funding for said client.

Contacts

Counsel to a Finnish multinational company against a Finnish company in a multimillion Euro EPC dispute in the renewable energy field.

Contacts

Counsel to a Finnish company before the Finnish Market Court in a merger control case subject to special expedited rules.

Contacts

Counsel to a Finnish company in negotiations with regard to the termination of a procurement contract avoiding lengthy litigation.

Contacts

Counsel to an international manufacturer against a Nordic company in a multibillion SEK dispute arbitrated in Stockholm under the SCC Rules and Swedish applicable law.

Contacts

Counsel to a Finnish forestry company in the District Court, Court of Appeal and before the Supreme Court in the largest ever Finnish follow-on damages litigation in which with claims amounting to 280 million euros.

Contacts

Counsel to a Central European company against a Russian corporation in a multimillion-dollar dispute arbitrated in Stockholm under the SCC Rules and Russian and Swedish applicable law.

Contacts

Counsel to a Polish investor in an SCC arbitration under the Poland-Cyprus BIT in an SCC arbitration.

Contacts

Counsel to a Finnish listed company against a Danish corporation in a high-value engineering dispute mediated and arbitrated in Copenhagen under the DIA Rules and Danish applicable law.

Contacts

Counsel to a European telecommunications company in a long-running ICC arbitration with a French corporation arising out of a joint venture located in Eastern Europe, with several billion euros in dispute.

Contacts

Counsel to a European telecommunications company in long-running, parallel VIAC arbitrations relating to a shareholder agreement.

Contacts

Counsel to the SPLM/A (South Sudan) in its boundary dispute with the Government of Sudan in the so-called Abyei arbitration under the auspices of the PCA under UNCITRAL Rules.

Contacts

Continuously counsel to Finnish and foreign parties in the drafting of contracts, especially with regard to dispute resolution provisions, as well as in the preparation of claims and settlement of disputes.

Contacts

Acted in over 25 arbitrations as Co-arbitrator, Sole Arbitrator and Chairperson on arbitral tribunals constituted under the ICC, SCC, DIA, LCIA and FAI Rules governed by Swedish, Finnish, Danish, English, Cypriot, New York and Swiss applicable law.

Contacts

Rankings

  • "Anna-Maria Tamminen provides high-quality legal services in dispute resolution and has special skills and knowledge.", Dispute Resolution, Legal 500, 2025
  • Ranked in Dispute Resolution, Chambers Europe, 2025
  • "Anna-Maria Tamminen is straightforward and good at communicating.", "She is very knowledgeable and quick to the point.", "Anna-Maria is a gem. She's sharp and insightful, pays attention to detail, is an effective communicator and is very open to the ideas and input of others.", "She is very well known in arbitration.", Dispute Resolution, Chambers Global, 2025
  • “Anna-Maria Tamminen's exceptional ability to effectively manage complex and sophisticated arbitration and litigation by skilfully identifying and prioritising key issues is highly commendable.”, Dispute Resolution, Chambers Global, 2024
  • “Her dedication, strategic thinking and attention to detail have consistently led to favourable outcomes, especially in navigating through the intricacies of legal proceedings.” “Anna-Maria Tamminen's exceptional ability to effectively manage complex and sophisticated arbitration and litigation by skilfully identifying and prioritising key issues is highly commendable.”, Chambers Global, 2024
  • "Anna-Maria Tamminen has very broad experience of international arbitration and is extremely hardworking. She has good understanding of our business and our needs", Dispute Resolution, Legal 500, 2024
  • “She is a great team player who always listens to the client”, Chambers Europe, 2024
  • "Anna-Maria Tamminen has unique knowledge of international arbitration practices and procedures.", Dispute Resolution, Legal 500, 2024
  • "Anna-Maria Tamminen is straightforward and good at communicating.", "She is very knowledgeable and quick to the point.", "Anna-Maria is a gem. She's sharp and insightful, pays attention to detail, is an effective communicator and is very open to the ideas and input of others.", "She is very well known in arbitration.", Dispute Resolution, Chambers Global, 2025
  • Ranked as Next Generation Partner, Dispute Resolution, Legal 500, 2024
  • "Anna-Maria Tamminen stands out from the others.", Dispute Resolution, Legal 500, 2024
  • Recommended in Who’s Who Legal Arbitration (Finland), 2024
  • Ranked as Thought Leader, Who’s Who Legal Arbitration (Finland), 2023
  • Ranked as Recommended, Who's Who Legal Arbitration (Global Leader), 2023
  • "Anna-Maria Tamminen earns strong endorsements as 'a very smart practitioner with an international outlook'.", Recommended in Who’s Who Legal Arbitration (Finland), 2023
  • "Anna-Maria Tamminen is smart, talented and experienced. She has the strategic eye needed to guide the customer through the process, while also taking into account the business context.", Dispute Resolution, Chambers Global, 2023
  • Selected as one of the world’s leading practitioners in Commercial Litigation, Who's Who Legal, 2022
  • Ranked as Thought Leader, Who’s Who Legal Arbitration (Finland), 2022
  • Recommended in Dispute Resolution, Legal 500, 2021
  • 'Anna-Maria Tamminen assists with post-M&A and competition-related disputes. She is reputed for her expertise in arbitration, frequently acting on international cases.', Dispute Resolution, Chambers Global and Chambers Europe, 2021-2022
  • Ranked as one of the Thought Leaders and Global Leaders in the Who's Who Legal – Arbitration (Finland) 2021, 2020 and 2019 editions
  • "Anna-Maria Tamminen is a very good lawyer with great international exposure which we appreciate. Coupled with a fundamental understanding of the legal issue, Anna-Maria Tamminen distils from the complex and provides a concise, hands-on and actionable path forward. " Anna-Maria Tamminen is “sharp, quick off the mark and capable of providing strategic advice.", Dispute Resolution, Legal 500, 2020
  • "Sources state that she is 'very hard-working.", Dispute Resolution, Chambers Global and Chambers Europe 2020
  • Ranked as "rising star" for Commercial Arbitration/Finland in the 2019 edition of Euromoney's LMG Rising Stars, Expert Guides, Legal Media Group
  • "Sources highlight her strong international capabilities, adding that they 'sing her praises highly' and that she is 'seriously impressive.'" Dispute Resolution, Chambers Global 2019
  • Ranked as one of the Thought Leaders in the Who's Who Legal – Arbitration (Finland) 2019 edition
  • "Excellent knowledge and experience on the EU law field as well as investment arbitration." Benchmark Litigation 2018
  • 'Anna-Maria Tamminen stands out for being "very well versed in international disputes and arbitration." Clients also appreciate her "quick response times" and ability to "listen to the client."', Dispute Resolution, Chambers Europe 2018
  • Ranked as "rising star" for Commercial Arbitration/Finland in the 2019 edition of Euromoney's LMG Rising Stars, Expert Guides, Legal Media Group
  • "Sources highlight her strong international capabilities, adding that they 'sing her praises highly' and that she is 'seriously impressive.'" Dispute Resolution, Chambers Global 2019
  • Ranked as one of the Thought Leaders in the Who's Who Legal – Arbitration (Finland) 2019 edition
  • "Excellent knowledge and experience on the EU law field as well as investment arbitration." Benchmark Litigation 2018
  • 'Anna-Maria Tamminen stands out for being "very well versed in international disputes and arbitration." Clients also appreciate her "quick response times" and ability to "listen to the client."', Dispute Resolution, Chambers Europe 2018

Memberships and Positions of Trust

  • LCIA Court, 2024–
  • Board of the SCC Arbitration Institute, 2024–
  • Member of the Editorial Board of the Journal of International Arbitration, 2015–
  • Country Reporter for Finland, ITA Board of Reporters, 2015–
  • Co-chair of the IBA Arbitration Committee’s ESG Subcommittee, 2021–2023
  • Executive Committee of the Swedish Arbitration Association, 2019–2023
  • Alternate Member Representing Finland, ICC Court of Arbitration, 2018–2024
  • Member of the Civil Procedure Law Expert Committee of the Finnish Bar Association, 2018-2022
  • Member Representing Finland (2014–2018) and Member of Task Force “Maximising the Probative Value of Witness Evidence” (2016–2018), International Chamber of Commerce’s Commission on Arbitration and ADR
  • International Co-Chair of ASA below 40, 2017–2020
  • Co-Chair of London Court of International Arbitration’s Young International Arbitration Group, 2013–2017
  • Past Chair (2012-2014) and Founding Member of the Young Arbitration Club Finland
  • Member of the Finnish Arbitration Association, European Users’ Council of London Court of International Arbitration (LCIA), Association Suisse de l’Arbitrage (ASA), Swedish Arbitration Association (SAA), ICC Young Arbitrators Forum (ICC YAF), Young Austrian Arbitration Practitioners (YAAP), Young Arbitrators Sweden (YAS)
  • Finnish Bar Association, member

Professional Background

  • Partner, Hannes Snellman, 2018–
  • Managing Associate, Hannes Snellman, 2016–2017
  • Senior Associate, Hannes Snellman, 2011–2015
  • Wilmer Cutler Pickering Hale and Dorr LLP, London, 2006–2010

Education

  • Skiljemannautbildningen (SAA and SCC arbitrator training), 2016–2017
  • FAI Arbitration Academy, 2014
  • LL.M. (International Business Regulation, Litigation and Arbitration, Fulbright Scholar), New York University School of Law, 2011
  • Master of Laws, University of Turku, 2006

Publications

  • Co-author of book chapters on Procedural Requirements for Ordering of Emergency Relief Ordered by an Emergency Arbitrator and Procedural Requirements for Provisional Reliefs Ordered by an Arbitral Tribunal in Provisional and Emergency Measures in International Arbitration (Edward Elgar Publishing, 2023) together with Ella Hiltunen, Isabelle Sundström Stridh, and Marcus Nyberg
  • Co-author of article “Digital Hearings and Digitalisation of Arbitration – How Should Digitalisation Be Reflected in the Modernisation of the Finnish Arbitration Act in Digital Hearings” (Norstedts Juridik, 2022), together with Ricardo Gomes
  • Co-author of the article “Protecting Confidentiality Within Arbitration Proceedings”, Stockholm International Arbitration Yearbook 2021, together with Viktor Saavola
  • Practice Guide: Litigation 2020 by Chambers & Partners (2020, 2021)
  • Kluwer Arbitration Blog, article on SCC Express, together with Marcus Nyberg (2021)
  • Getting the Deal Through – Arbitration Finland Chapter together with Lehto, Tyynysniemi, and Rautiainen (2020)
  • Getting the Deal Through – Arbitration Finland Chapter together with Lehto and Tyynysniemi (2019)
  • Getting the Deal Through – Arbitration Finland Chapter together with Järvinen, Bygglin, and Heikkinen (2018)
  • Chambers eDiscovery & Disclosure Guide Finland Chapter together with Järvinen, Bygglin, and Heikkinen (2018)
  • Arbitration Agreement in Ehrström, Timonen, Turunen (Ed.) Arbitration in Finland, YACF publication (2017)
  • Issue Conflicts as Basis for Challenge of an Arbitrator – A New First in Nordic Arbitration Practice? Scandinavian Series of Law vol. 63 (2017), pp. 331–354
  • Case comment “Finland: A Party Can Recover Costs of Court Proceedings for Interim Measures in a Subsequent Arbitration” in ICC Dispute Resolution Bulletin 2017 Issue 2
  • Kluwerarbitration blog “Arbitrator-ordered Costs of Injunctive Relief Proceedings in National Court: When Should a Party Be Able to Recover its Costs?” 6 April 2017
  • Several case comments for ITA Board of Reporters (together with Mika Savola and Ina Rautiainen), Kluwer Arbitration (2015–)
  • “The Obligation to Pay the Advance on Costs under the Vienna Rules and Austrian Law”, Austrian Arbitration Yearbook 2009, Manz (2009)

Speaking Engagements

  • September 2024, IBA Annual Conference, Mexico City, speaker
  • September 2024, Vilnius Arbitration Day, speaker
  • September 2024, Copenhagen Arbitration Day, speaker
  • April 2024, Law and Climate Change Summit, Stockholm, speaker
  • April 2024, Alma Talent's seminar on contractual disputes (Sopimusriitapäivä), speaker
  • August 2023, Student Investment Summit, Aalto Investment Club, keynote speaker
  • June 2023, Swedish Arbitration Association, Annual Meeting
  • May 2023, Dutch Arbitration Day 2023, moderator
  • April 2023, GAR Live Construction, Paris, speaker
  • April 2023, ICC European Conference, Paris, speaker
  • Speaker, Finnish Arbitrator Training (Välimieskoulu), October 2022
  • August 2022, Swedish Arbitration Days, moderator
  • November 2021, SAA seminar on the probative value of witness evidence, Stockholm, moderator
  • September 2021, FAI Arbitrator Training, speaker
  • ICC ePIDA Training on International Commercial Arbitration, lecturer
  • September 2021, LL.M. in Investment Treaty Arbitration, Uppsala University, lecturer
  • August 2021, Mute-Off Thursdays, ‘ISDS in the Nordics’, speaker
  • June 2021, Swiss Arbitration Launch, moderator
  • March 2021, CIArb YMG World Tour, recent developments in China and Scandinavia, speaker
  • November 2020, Hannes Snellman webinar ‘How to kill disputes quickly’
  • October 2020, SAA webinar, moderator
  • May 2019, IFCAL Conference, Helsinki, moderator
  • April 2019, Copenhagen Arbitration Day, Copenhagen, speaker
  • March 2019, Future of International Arbitration, London, speaker
  • February 2019, Winter Academy, University of Vienna, Austria, speaker