Denis V. Keseris
Counsel, Ottawa
UK Chartered Patent Attorney


Phone: 613.232.2486
Fax: 613.232.8440
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  • University of Ottawa B.A.Sc . (Electrical, Electronics and Communications Engineering) 2002
  • Queen Mary School of Law, University of London P.G.C. Intellectual Property Law 2005
  • European Patent Attorney 2008
  • UK Chartered Patent Attorney 2009
  • European Designs Attorney 2009

Denis Keseris has over 15 years of experience in the field of intellectual property. As part of the firm’s IP Strategy group, his practice is mainly focused on advising clients in relation to strategic portfolio growth and utilization. Prior to joining the firm, Denis spent most of his career practicing as a UK & European Patent Attorney in London and Paris, both as in-house counsel and in private practice.

Denis has extensive experience in the preparation and prosecution of patent applications in North America and Europe, particularly in the areas of telecommunications, software, consumer electronics and medical devices. He has also represented clients in ex-parte hearings before the Boards of Appeal of the European Patent Office (EPO) and inter-partes proceedings before the Opposition Division of the EPO, and has prepared and consulted on patent invalidation actions before a number of European courts.

Denis has developed his strategic IP expertise over a number of years, by providing commercially-focused strategic counselling in contentious IP matters, in freedom to operate projects for large European medical devices manufacturers, and IP due diligence and portfolio valuation projects for London-based private equity and venture capital investors.

In Paris, Denis was IP Counsel for Bell Labs, where he was involved in a range of activities relating to the creation and strategic exploitation of standard-essential patent rights in Europe and the United States. He also participated in the preparation of submissions to standards bodies, and acted as a patent essentiality evaluator for a large standards licensing entity. His experience at Bell Labs gave him invaluable insight into the practical needs and constraints of corporate IP departments seeking to grow and capture business value from their portfolio, whilst at the same time being under pressure to commoditize outsourced IP services.

Prior to being a Patent Attorney, Denis was a Patent Examiner at both the Canadian Intellectual Property Office (CIPO) and the UK Intellectual Property Office (UK IPO). This experience provided him with an understanding of what motivates patent examiners, as well as some of the inner workings of modern patent offices.

Denis has worked with a wide range of clients in Europe, Asia and North America, including SMEs looking to attract investment and increase their returns on IP investment, large multinational clients seeking to strengthen their existing portfolios and assert their rights through litigation and licensing and investors backing some of the most innovative technology companies on either side of the Atlantic.

IP Management & Strategic Counselling
Industrial Designs
Software/Information Technologies


  • Fellow, Chartered Institute of Patent Attorneys (CIPA)
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