Klaus Ilmonen

Partner, Doctor of Laws
+358 9 2288 4378
+358 40 831 1868
Hanna-Mari Mudi

Assistant's telephone:

+358 9 2288 4382


Klaus Ilmonen heads our Capital Markets practice in Helsinki. His practice includes equity capital markets and other corporate transactions involving public corporations. He has considerable experience from public takeovers, as well as from cross-border transactions. He also works with governance of public corporations.
Klaus serves on a consultative group for developing EU corporate finance regulation and has participated in drafting Finnish takeover regulation. He also teaches securities regulation at the University of Helsinki.
Klaus has qualified as an attorney in the State of New York, and practised U.S. securities law in the London office of the law firm Cleary, Gottlieb, Steen & Hamilton, where he represented European issuers and underwriters in international securities offerings. He also worked on international M&A transactions.
Klaus has been a visiting researcher at Harvard Law School, he holds a LL.M. degree from Columbia Law School in New York and a doctorate in law from the University of Helsinki.

He has served as an officer with Finnish forces in Kosovo and Afghanistan. He has lectured on operational law in Finland and abroad.


  • Counsel to Terveystalo in its IPO and listing on the Nasdaq Helsinki stock exchange, 2017.
  • Counsel to lead manager SEB (publ.) Helsinki branch in the transfer of Robit Oyj from First North Finland to the main list of Nasdaq Helsinki, 2017.
  • Counsel to Powerflute Oyj in the recommended cash offer for Powerflute by Nordic Packaging and Container (Finland) Holdings Oy an affiliate of Madison Dearborn Partners, LLC. 2016.
  • Counsel to Biotie Therapies Corp. in the public tender offer of the shares and other securities in Biotie Therapies by Acorda Therapeutics, 2016.
  • Counsel to Alma Media Corporation on its exchange offer for the shares and options in Talentum Oyj.
  • IPO of Asiakastieto Group Oyj - Counsel to the issuer, 2015.
  • IPO of Verkkokauppa.com Oyj - Counsel to the issuer, 2014.
  • OP-Pohjola Group EUR 3,3 billion tender for Pohjola Bank - Counsel to Pohjola Bank, 2014.
  • Counsel to Microsoft Corporation on its Acquisition of Nokia Devices & Services from Nokia Corporation for EUR 5,44 billion, 2013.


  • "Sources describe him as an 'experienced partner, very diligent and knowledgeable' with 'superb skills in all relevant areas.' Clients also note that 'he is a positive person who always wants to make sure whatever needs to be done gets done.', Chambers Global 2018
  • Ranked among the best lawyers in Capital Markets in the 2015, 2016 and 2017 editions of Chambers Europe
  • Ranked as an expert based abroad in Finland in Capital Markets USA in the 2017 edition of Chambers Global
  • Described as "driven, professional and always strives for the highest quality.", Chambers Europe 2016
  • Leading individual, Capital Markets, Legal 500, 2016 and 2017
  • "Klaus Ilmonen is ‘one of the few experienced lawyers in the Finnish IPO market’ ", Capital Markets, Legal 500, 2015
  • Ranked as a Highly regarded  lawyer in Capital Markets in the 2014, 2015, 2016, 2017 and 2018 editions of IFLR1000
  • Ranked among the best lawyers in the 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016 and 2017 editions (Helsinki: Capital Markets, Mergers and Acquisitions) of Best Lawyers®


  • Member of the Consultative Working Group on Corporate Finance of the European Securities Markets Authority (ESMA)
  • Member of the expert group on securities regulation of the Finnish Bar Association
  • Managing director of the Mannerheim Foundation


  • Doctor of Laws, University of Helsinki, 2016
  • Harvard Law School, Visiting Researcher, 2011 - 2012 (Jan.)
  • Partner, Hannes Snellman, 2007
  • Associate, Cleary, Gottlieb, Steen & Hamilton, London, 1999 - 2002
  • LL.M. (Stone Scholar), Columbia University, 1999