Anna-Maria Tamminen

Partner | Helsinki
English, Finnish, Swedish, French, German

Anna-Maria specialises in dispute resolution, with a special focus on complex, international disputes. She currently represents parties in mediations, national and international arbitrations, as well as administrative and civil litigations both in Finland and Sweden. She has also acted for clients before the ECJ and the Finnish and Swedish Supreme Courts.

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 telecoms, energy and renewables, forestry, construction, pharmaceuticals, logistics and financial services. 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 20 international arbitrations under the ICC, SCC, FAI, DIA and LCIA Rules. The cases have been subject to Swedish, Finnish, Danish, Cypriot, Swiss and English law.

She regularly publishes articles, presents at conferences and lectures on dispute resolution topics. She is an alternate member of the ICC Court of arbitration representing Finland scrutinising both commercial and investment treaty awards as well as appointing arbitrators as part of the ICC Court’s work. She is currently also a member of the Executive Committee of the Swedish Arbitration Association.

Anna-Maria is trained in both common and civil law legal systems and is admitted to practice as an attorney both in 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.

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.

Chambers Global 2023 | Dispute Resolution

Relevant References

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.

Pontus Ewerlöf

Pontus Ewerlöf

Partner | Stockholm
Anna-Maria Tamminen

Anna-Maria Tamminen

Partner | Helsinki
Martin Rifall

Martin Rifall

Partner | Stockholm


Veolia Services Suomi Oy, Metsä Fibre


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


Counsel to Veolia Services Suomi Oy

Katja Perätalo

Katja Perätalo

Specialist Partner | Helsinki
Maria Landtman

Maria Landtman

Partner | Helsinki
Emmi Nuutila

Emmi Nuutila

Senior Associate | Helsinki
Kristina Leibssle

Kristina Leibssle

Senior Associate | Helsinki
Anna-Maria Tamminen

Anna-Maria Tamminen

Partner | Helsinki
Klaus Metsä-Simola

Klaus Metsä-Simola

Partner | Helsinki
Päivi Tammilehto

Päivi Tammilehto

Counsel | Helsinki

Represents a European State in the setting aside proceedings of an investment treaty award before the Svea Court of Appeal, Swedish Supreme Court and the European Court of Justice with a value of several hundred million euros.

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

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

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

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

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

Represented 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.

Represented 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.

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

Represented 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.

Represented 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.

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

Represented 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.

Continuously advises 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.

Acted in over 20 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 and Swiss applicable law.


  • "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
  • Recognised 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
  • 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 one of the World’s leading Arbitration lawyers (Finland), Who’s Who Legal: Arbitration 2018
  • Ranked as a notable practitioner (Dispute Resolution), Chambers Europe 2018
  • Ranked as "a Rising Star" in Commercial Arbitration, Expert Guides, Legal Media Group 2018
  • One of the most highly ranked individuals in the non-partner category of Who’s Who Legal 2017: Future Leaders – Arbitration and described as "persistent and experienced for her age, dedicated and bright"
  • Ranked as "a Rising star" in the 2015 edition (Dispute Resolution) of Chambers Europe 2015, described as “really capable and good in international cases” in the 2016 edition (Dispute Resolution) of Chambers Europe 2016, recognised as an "associate to watch" in the 2017 edition (Dispute Resolution) of Chambers Europe 2017

Memberships and Positions of Trust

  • Finnish Bar Association, member
  • Attorney-at-law and Counsellor in the State of New York, USA


  • Swedish Arbitration Association, Executive Committee, 2019-
  • ICC Court of Arbitration, alternate member representing Finland, 2018-
  • Member of the Civil Procedure Law Expert Committee of the Finnish Bar Association, 2018-
  • International Chamber of Commerce, Commission on Arbitration and ADR, member representing Finland (2014-2018), Task Force “Maximising the Probative Value of Witness Evidence” member (2016-2018)
  • ASA below 40, international co-Chair (2017-2020)
  • London Court of International Arbitration, Young International Arbitration Group, Co-Chair (2013-2017)
  • Young Arbitration Club Finland, past Chair (2012-2014) and Founding Member
  • 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)
  • Journal of International Arbitration, member of the Editorial Board (2015-)
  • ITA Board of Reporters, country reporter for Finland (2015-)


  • 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), p. 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)

Education and Professional Background

  • Skiljemannautbildningen (SAA and SCC arbitrator training) 2016-2017
  • FAI (Arbitration Institute of the Finland Chamber of Commerce) Arbitration Academy, 2014
  • LL.M. in International Business Regulation, Litigation and Arbitration, New York University School of Law, USA 2011 (Fulbright Scholar) including courses on international investment law, international dispute resolution, WTO law and international arbitration
  • Master of Laws, University of Turku, Finland 2006
  • Erasmus exchange year, University of Vienna, Austria 2004-2005


  • Partner, Hannes Snellman Attorneys Ltd, Helsinki 2018-
  • Managing Associate, Hannes Snellman Attorneys Ltd, Helsinki 2016-2017
  • Senior Associate, Hannes Snellman Attorneys Ltd, Helsinki, 2011-2015
  • Foreign Associate, Wilmer Cutler Pickering Hale and Dorr LLP, London, 2006-2010
  • Internships at law firms and ministries in the United Kingdom, Finland and Austria

Recent Speaking Engagements

  • 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
  • December 2018, CEA Mediation Commission event, Madrid, speaker
  • November 2018, ASA below 40, Fall Seminar, Zurich Switzerland, Co-chair
  • October 2018, Swedish Law Day, Moscow, speaker
  • October 2018, GAR Live Vienna, Vienna Austria, Panellist
  • September 2018, Swedish Arbitration Days, Stockholm Sweden, Panellist
  • May 2018, LCIA European Users’ Council Symposium, Tylney Hall, co-chair
  • April 2018, Summit on Global Dispute Resolution, New York, panellist
  • April 2018, DIS40 Spring Seminar, Zurich, panellist
  • April 2018, ICAL Programme University of Stockholm, Stockholm, lecturer
  • March 2018, SCC Seminar on Investment Arbitration, Warsaw, panellist
  • March 2018, Cross-border transactions course, University of Helsinki, lecturer

Blog Posts by Anna-Maria Tamminen

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