Thommessen is one of Norway's leading commercial law firms with offices in Oslo, Bergen and London. We have at total of 300 highly qualified employees. 200 of the firm's employees are lawyers who together cover 17 areas of expertise. We provide advanced legal services to corporate clients and the public sector, both domestically and internationally.

A firm with a long tradition in Norwegian legal history
The Thommessen story began on 19 January 1856 when Hans Christian Grønn established a private law practice in Oslo. Grønn sought to free the legal profession from the public sector and to make business law more international. Since then, the firm has had close ties to many of the country’s leading companies within industry, finance, trade and other sectors. Among other things, we assisted in the establishment of Norsk Hydro-Elektrisk Kvælstof-aktieselskap (Norsk Hydro) in 1905.

The 1990s was a decade of growth and large mergers in the Norwegian legal services industry. This development was initiated by the establishment of Thommessen & Krefting in 1990 from the merger between Thommessen Karlsrud Heyerdahl & Brunsvig and Krefting & Løchen (established 1954). In 1991 Thommessen & Krefting merged with Norway’s largest law firm outside of Oslo: Greve, Greve, Greve & Lorentzen in Bergen (established 1928). In 1993 the firm acquired a significant practice within shipping and offshore when parts of the law firm Lund & Co were merged into Thommessen and the name of the firm became Thommessen Krefting Greve Lund. From 1 September 2009 our business name was changed to "Advokatfirmaet Thommessen AS". The change is due to a desire to simplify the previous name.