Michael Sitsen advises on public commercial law and public procurement law. He has particular industry expertise in the areas of transportation (bus and rail transport), mobility and energy infrastructure. He regularly advises public clients and companies on large-volume and complex projects, in particular procurement and infrastructure projects. A further focus of his advisory practice is on subsidy law as well as environmental, construction and planning law.

Michael Sitsen joined orka as a salary partner in 2010. He was appointed partner in 2017. Previously, he was a lawyer at an international commercial law firm in Düsseldorf.

Michael Sitsen studied law in Frankfurt am Main and Cologne and was a research assistant at the Institute for Public Law at the Rheinische Friedrich-Wilhelms-Universität in Bonn. He received his doctorate from the University of Bonn in 2008. Michael Sitsen is a specialist lawyer for administrative law and a specialist lawyer for public procurement law. He publishes regularly in specialist 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.