Michael Sitsen advises on public commercial law as well as public procurement law. He has special knowledge in the transport sector (bus and rail transport) and regularly advises public clients and companies on large-volume and complex procurement projects. His practice also focuses on environmental, construction and planning law as well as on specific issues of renewable energy law (EEG).

In 2010 Michael Sitsen joined orka as Salary Partner and in 2017 he was appointed Partner. Previously, he had worked as a lawyer for an international commercial law firm in Düsseldorf.

Michael Sitsen studied law in Frankfurt/Main and Cologne and also worked as a research assistant at the Institute for Public Law at Rheinische Friedrich-Wilhelms University in Bonn. He received his Doctorate in Law from the University of Bonn in 2008. Michael Sitsen is qualified as Certified Specialist in Administrative Law and Public Procurement Law (Fachanwalt sowohl für Verwaltungs- als auch Vergaberecht). He publishes regularly in professional journals and on the public procurement blog and is also a regular speaker on public procurement law.

Michael Sitsen is also a member of the board of the Association of Specialist Lawyers for Public Procurement Law (VFV) e.V., as well as a member of the Deutsche Verkehrswissenschaftliche Gesellschaft (DVWG) e.V., the Forum Vergabe e.V. and the Arbeitsgemeinschaft Verwaltungsrecht im Deutschen Anwaltverein.