Advokatfirmaet Thommessen AS's wide-ranging EU/EEA and competition practice encompasses antitrust, public procurement, and state aid regulation. As a result of its broad sector expertise spanning from telecoms to energy, the firm receives a varied stream of work. Practice lead Heidi Jorkjend provides clients with advice and legal project management in relation to antitrust investigations. Siri Teigum is experienced in cases in the EFTA Court and CJEU, as well as in merger clearance matters. Eivind J Vesterkjaer's expertise across all aspects of competition law bolsters the team’s offering, while Wenche Sædal chiefly focuses on EU/EEA law and state aid. In a team development, Svein Terje Tveit joined from Arntzen de Besche in December 2025.

Legal 500 Editorial commentary

Accolades

Client satisfaction: Sector knowledge

Client satisfaction: NPS ®

Testimonials

Collated independently by Legal 500 research team.

'The partners are all second to none.'
‘This is simply the strongest EU and competition law team in Norway.’
‘Eivind J Vesterkjaer is, with his unique combination of commercial understanding, attention to detailed regulations, and the ability to create friendly and cooperative discussions with the clients, a dream to work with.’
‘Knowledgeable, very responsive and understanding of the client's situation - highly solution oriented.’
‘I recommend Eivind J Vesterkjaer.’
‘Thommessen’s competition team is skilled and experienced, and manages to balance the ability to identify risks and find pragmatic solutions to address them.’

Key clients

SpareBank 1
Kongsberg Gruppen
Veidekke ASA
Ringnes ASA
Gyldendal ASA
Lindum AS
Halliburton
Sandbrook Capital and Public Sector Pension Investment Board (PSP)
Vestdavit AS
Eviny AS
BAMA
NorgesGruppen ASA

Work highlights

Advising NorgesGruppen ASA in connection with the Norwegian Competition Authority's issuance of a NOK 5bn fine relating to an alleged 'by effect' infringement based on information exchange.

Advised Kongsberg Defence & Aerospace AS on the establishment of a joint venture with Thales within defence communications.

Advising DNB ASA on its acquisition of Carnegie Holding AB - a securities company with activities in Norway, Sweden and Denmark - and assisting with merger filing and clearance in Norway.

Lawyers

Hall of Fame

The lawyers at the very top of the profession, widely known and respected by peers and clients for their longstanding involvement in market-leading work.