Glossary of competition terms

This Glossary is based on definitions from DG COMP’s Glossary of terms used in EU competition policy (© European Union, 2002) and the OECD’s Glossary of industrial organisation economics and competition law (© OECD, 1993). Each term is enriched with references of EU and national case laws from the e-Competitions Bulletin and Concurrences Review.


A concentration arises either where two or more previously independent undertakings merge (merger), where an undertaking acquires control of another undertaking (acquisition of control), or where a joint venture is created, performing on a lasting basis all the functions of an autonomous economic entity (full-function joint venture).© European Commission

See the Merger Regulation, Commission Consolidated Jurisdictional Notice under Council Regulation (EC) No 139/2004 on the control of concentrations between undertakings (OJ C95 of 16.04.2008)

An amalgamation or joining of two or more firms into an existing firm or to form a new firm. A merger is a method by which firms can increase their size and expand into existing or new economic activities and markets. A variety of motives may exist for mergers: to increase economic efficiency, to acquire market power, to diversify, to expand into different geographic markets, to pursue financial and R&D synergies, etc. Mergers are classified into three types:

  • Horizontal Merger: Merger between firms that produce and sell the same products, i.e., between competing firms. Horizontal mergers, if significant in size, can reduce competition in a market and are often reviewed by competition authorities. Horizontal mergers can be viewed as horizontal integration of firms in a market or across markets.
  • Vertical Merger: Merger between firms operating at different stages of production, e.g., from raw materials to finished products to distribution. An example would be a steel manufacturer merging with an iron ore producer. Vertical mergers usually increase economic efficiency, although they may sometimes have an anticompetitive effect.
  • Conglomerate Merger: Merger between firms in unrelated business, e.g., between an automobile manufacturer and a food processing firm. © OECD