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LATEST NEWS: 2014 Assessment of Chile's Merger Control is launched in Santiago - 21 July 2014

The OECD carried out a in-depth study of Chile’s merger control regime which assesses the main existing issues in the current system and provides suggestions for improvement based on OECD and international standards. View the report 

Mergers: An integral part of the competition landscape to be closely monitored

Almost all systems of competition law provide for control of mergers, to prevent companies from joining together to eliminate competition between them.

A merger could be a complete union of two or more companies, a more one-sided takeover or the transfer of parts of one firm to another.

Deciding whether a merger will harm competition can require sophisticated economic analysis of markets and the effects of the transaction.  Yet this sophisticated analysis must in most jurisdictions be carried out to strict deadlines so as to protect the procedural rights of all affected parties.

Why do competition authorities analyse mergers?

Most mergers are beneficial to competition, or at least do no harm to it, so competition authorities typically conduct a quick screening exercise to identify the exceptions.  In, mergers between competitors can result in very large costs to consumers and to the economy more generally, so it is essential that authorities have the power and skills to investigate effectively and to remedy any potential problems they find (including by blocking the merger).

Mergers between companies that do not directly compete (such as a ‘vertical’ merger between a supplier and its customer) rarely raise competition concerns; but when they do, they require very sophisticated economic analysis to assess whether the effects are anti-competitive or efficiency-enhancing.



Debating merger control at the OECD

The OECD provides competition agencies with opportunities to debate the latest developments in merger control between themselves, as well as with international experts and the business community.  These debates cover the whole process from the initial notification of a merger, to assessment of the determination of remedies and finally ex post evaluation of the results.  The OECD has been closely involved in the development of common principles for the standard of review of mergers.  This extends to principles for co-operation between competition authorities when assessing international mergers, an area in which the OECD is currently focusing its efforts.


Documents and links

List of all roundtables on mergers

Geographic market definition across national borders, 2016


Agency decision-making in merger cases: Prohibition and conditional clearances, 2016

Big data: Bringing competition policy to the digital era, 2016

Public interest considerations in merger control, 2016

Jurisdictional nexus in merger control regimes, 2016 

Oligopoly markets, 2015

Remedies in cross-border merger cases, 2013

Provisions in co-operation agreements on competition, 2014

Enhanced Enforcement Co-operation, 2014

Investigations of Consummated and Non-notifiable Mergers, 2014

Definition of Transaction for the Purpose of Merger Control Review, 2013

Role and Measurement of Quality in Competition Analysis, 2013

The Role of Efficiency Claims in Antitrust Proceedings, 2012

Market Definition, 2012

Impact Evaluation of Merger Decisions, 2011


OECD Recommendation on Merger Review 2005

Country experiences with the OECD Recommendation on Merger Review


For further information on work related to mergers, please contact us at


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