INTRODUCTION Assimakis KOMNINOS Local Partner, White & Case, Brussels 1. At the time of the adoption by DG Competition of the 2005 Discussion Paper and the 2009 Guidance Paper on exclusionary abuses, the treatment by EU competition law of the so-called “efficiency defence” arose as a topic of great academic and practical importance. It is by no chance that the emergence of this notion had to wait for the advent of the “new economic approach” in Article 102 TFEU. Indeed, as late as 2002, the Commission’s Glossary of Terms used in EU competition law [1] had not a single reference to the term “efficiency,” not to mention “efficiency defence,” although it did speak about practices that were “objectively justified.” 2. Nowadays, the concept of “efficiency defence” is well-accepted and no