Nils H. Thommessen has extensive experience with assisting financial advisors, private equity funds and other financial and industrial investors with acquisitions, mergers and other corporate matters. Nils assists in all relevant aspects of transactions, both nationally and internationally. He is widely used as a legal and strategic advisor in the follow-up of clients’ investments.

Nils is ranked as one of Norway's most prominent experts on mergers and acquisitions by Chambers and Partners, Legal 500 and IFLR1000. In December 2016, Finansavisen presented him as one of Norway's leading negotiators.

Nils Thommessen is described by market sources as "a born leader and a very skilled lawyer who it takes a lot to beat." He has a wealth of experience assisting investors and financial advisers on corporate transactions both domestically and internationally.

Chambers Europe, 2018

- An exceptionally skilled negotiator. Solution oriented and commercial. One of the best Norwegian negotiators.

Finansavisen 2017


  • Nils H. Thommessen has assisted in a very large number of transactions for our clients. Additionally, he is a sought after strategist with respect to our clients commercial positioning, and a very well repudet advisor for both Private Equity firms and industrial corporations.

Professional Experience

  • Partner, Wiersholm, 1997 (Managing Partner, 2012-2018)
  • Lawyer, Wiersholm, 1992
  • Lawyer, Ince & Co, London, 1991-1992


  • Cand. jur., University of Oslo, 1990

Board Memberships

  • Advisory Board, Center on the Legal Profession, Harvard Law School, Member
  • Advisory Board, Best Lawyers International, Member
  • Right To Play, Board Member