Marcel van Kooij

Patent Attorney at Arnold & Siedsma
Ranked in Netherlands
IAM Research

The Patent 1000 focuses exclusively on patent practice and has firmly established itself as the definitive 'go-to' resource for those seeking world-class legal patent expertise.

Recommended - Individuals: prosecution

Arnold & Siedsma has been providing ironclad IP protection for over a century, and the firm today employs 156 experts operating out of 12 offices in the Netherlands, Belgium and Germany. In Amsterdam the team thrive in the computer science, electrical engineering, mechanical engineering and physics arenas, and has several instructions keeping them occupied. Arjen Hooiveld and Martin Luten act as the European representatives for Japanese manufacturer NSK Ltd. Hooiveld frequently counsels Japanese companies with their European patents, and “Martin is hands-on and strategically strong, ensuring the best results”. Joining them in the guide this year is IAM Patent 1000 newcomer Marten Bosma, who understands the business criticality of patents, thanks to his time spent in-house as a scientific researcher and business developer. Bart Jacobs and Paul Hylarides have been assisting Samsung with regard to several of their business units; Jacobs has an excellent ability to translate technical inventions into commercially viable products, and Hylarides teamed up with fellow Eindhoven-based partner Rogier Brouwer to support Dredging International NV and its associated companies with everything from invention harvesting and searches to freedom-to-operate advice and oppositions. The team also has a solid life sciences offering, where Petri van Someren and Marcel van Kooij shine. Van Someren is a seasoned practitioner with immense expertise in biotechnology and van Kooij is not only a reference for prosecution services but also for licensing agreements. Holding down the fort on the contentious side is Michiel Rijsdijk, an eloquent and compelling advocate with a profound ability to enhance the value of his clients’ intangible assets.

Marcel van Kooij's Profile

Marcel van Kooij is a European patent attorney and partner at Arnold & Siedsma. Mr van Kooij is skilled in the many aspects of providing patent services, such as:

  • writing and prosecuting patent applications;
  • defending patent applications before the EPO (opposition and appeal);
  • seeking the nullification of patents of possible competitors before the EPO, the Patent Centre and in court;
  • advising clients on the development or strengthening of their IP position;
  • negotiating licence or transfer agreement;
  • producing second opinions; and
  • advising on additional IP protection, such as supplementary protection certificates and plant breeders’ rights.

Mr van Kooij advises and supports many large national and international clients on their IP and innovation policy, but is also involved with start-ups, particularly in the field of biotechnology.

In addition to his patent law expertise, Mr van Kooij has become a specialised, proactive adviser whose main concerns are tailored service, cost control and creativity combined with a long-term vision.

Mr van Kooij approaches a case with a pragmatic attitude that gives priority to clarity and transparency for the client. The starting point in a case has to be that one (the client’s expertise) plus one (Mr van Kooij’s expertise) equals three.

In addition to providing patent services, Mr van Kooij derives great satisfaction from sharing his knowledge. He teaches at the University of Strasbourg (Centre for International Intellectual Property Studies) and is a tutor at the Institute of Professional Representatives before the European Patent Office. He is also actively involved in increasing IP awareness.

Firm Profile

Arnold & Siedsma is an all-round service provider for the protection of intellectual property. Since 1920 your creations have been our motivation. We have 100 years of experience in the legal protection of intellectual property of inventions, trademarks and designs for individuals as well as for large multinationals, in the Netherlands and abroad. In addition to our offices in the Netherlands, Germany, Belgium and Switzerland, Arnold & Siedsma has an extensive global network of agents so that we can protect your rights anywhere in the world.

Arnold & Siedsma has more than 60 in-house technical and legal experts with knowledge of all the key innovative sectors, from biotechnology and pharmaceuticals to semiconductors and software. Each client is assigned a patent attorney who specialises in the relevant, specific discipline. Our trademark and design attorneys are the best partners for all issues related to your trademarks or protecting the unique design of your products. Our IP attorneys at law can help you with anything related to legal procedures, such as enforcing your rights.

ISO 9001 certified

For the past 100 years, we have been a reliable partner for our clients with regard to all IP issues. In 2015 we became the first large Dutch IP agency with foreign offices to be ISO 9001 certified. This certification is valid for all our offices in the Netherlands and abroad. We are proud of our ISO 9001 certification because it represents what our firm stands for: say what you do, do what you say, prove it.


At Arnold & Siedsma we believe in customised work and this can be seen in the way we operate. You can count on our personal attention, a fixed account manager and a regional office in your area.

The lines of communication with our specialists are short and personal. Service is our top priority. We stay in close touch with our clients so that we can provide you with a fast and responsive service. With offices throughout the Netherlands and Belgium, our specialists are always within proximity. At Arnold & Siedsma you will be assigned one or two dedicated account manager(s). The long-term relationship ensures that they know your business and strategy, which in turn means that they will be able to give you the correct advice for your business, in line with your multi-annual planning. Your account manager will maintain regular contact with you. The protection of your innovation is of great economic value, but can also be costly. This is why, at Arnold & Siedsma, we attach great importance to clear communication before, during and after each procedure.

Because we are a full-service provider, we have in-house specialists from all IP disciplines. Our patent attorneys, trademark and design attorneys and lawyers work closely together. We can pull together a team from several disciplines for our clients so that problems and issues are communicated between the different disciplines quickly, seamlessly and without unnecessary costs. Arnold & Siedsma is uniquely positioned as a service provider in the Netherlands thanks to this team-based approach.


Our patent attorneys have years of experience in supporting companies in various sectors and are therefore up to date with developments in your discipline. This technical knowledge and experience guarantee the optimisation of your rights. The main sectors in which Arnold & Siedsma is active are chemistry and pharmacy, electrical engineering and physics, mechanical engineering, biotechnology and food, materials and software. Our experienced specialists can assist you with the protection of your intellectual property in these sectors.


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