Erik Thyness has extensive experience as an advisor to energy and industrial companies, financial institutions and investment groups in relation to merger, acquisitions and capital market transactions as well as other matters requiring insight into finance and accounting in addition to legal expertise. Mr. Thyness also acts in disputes involving company law, securities law, tax, pensions and contract law.

Erik Thyness is the co-author of the books "Cross Border Mergers in Europe" (Brussels, 1989) and Boye/Meyer (editors.), "Fusjoner og oppkjøp" [Mergers and Acquisitions] (Oslo, 2008).

Mr. Thyness is ranked as one of the top lawyers within his areas of expertise in all recognised lawyer rankings, including as "star performer" within M&A/Corporate by Chambers.

Erik Thyness is widely recognised as an outstanding practitioner in the fields of M&A and capital markets, with one source enthusing that "I have never met a lawyer so accomplished in so many different legal areas."

Chambers Europe, 2018


  • Mr. Thyness has advised on a substantial number of the most important transactions in the Norwegian market over three decades, including the merger of Nycomed and Amersham, the establishment and IPO of Yara, the merger of Statoil and Norsk Hydro's oil and gas business, the establishment, IPO and subsequent sale of Statoil Fuel & Retail, the establishment of Sapa and Schibsted's joint ventures with Telenor, Singapore Press Holdings and Naspers.

Professional Experience

  • Partner, Wiersholm, 1996 (Managing Partner, 2006-2012)
  • General Counsel, Hafslund Nycomed AS, 1993-1996
  • In-house Counsel, Norsk Hydro ASA, 1988-1989 and 1991-1993
  • Deputy Judge, Sør-Gudbrandsdal District Court, 1989-1990


  • Admitted to the Supreme Court, 2007
  • Cand. jur., University of Oslo, 1987