Günther Rensen is Professor of Corporate Law at Utrecht University (0.6 FTE) and also works as Knowledge Counsel/Deputy Civil-Law Notary at A&O Shearman in Amsterdam (0.4 FTE). His research concerns corporate law in a broad sense, but with a focus on its notarial aspects, such as: incorporation, (re)structuring and dissolution of legal entities. In addition to the public limited company (NV) and the private limited liability company (BV), he focuses in particular on associations, cooperatives, mutual insurance companies and foundations. For example, he is the editor of the volume of the Asser series on these legal forms (Asser 2-III, latest edition 2022). He is also co-author of the Asser part 2-IIa on the incorporation, equity and shares of the NV/BV, the most recent edition of which is from 2024.

Günther is editor of the Weekblad voor Privaatrecht, Notariaat en Registratie  (WPNR), a private-law weekly with a special focus on the notarial practice. Since 2018, he has also been editor of the journal Jurisprudentie Onderneming en Recht (JOR).

Günther is a member of the Combined Company Law Committee of the Netherlands Bar Association (NOvA) and the Royal Dutch Association of Civil-Law Notaries (KNB). On behalf of these professional organisations NOvA and KNB, this committee issues recommendations on proposals for corporate law legislation and regulations. 

He also regularly provides postgraduate training for law firms, notary offices and other organizations (insurers, municipalities). As of 2022, Günther is a member of the Expert Group on the Modernisation of NV Law set up by the Dutch Ministry of Justice and Security.