Key Amendments To Law 3959/2011, Including Modernization Of Greek Merger Control, Reinforcement Of HCC Sanctioning Powers And Increase Of Use Of Digital Tools

Our Competition Law Briefing Special Edition analyses the key amendments to Law 3959/2011, including modernization of Greek merger control, reinforcement of HCC sanctioning powers and increase of use of digital tools, including:

1. Introduction
2. Key Takeaways
3. Final Remarks

A. Introduction

1. Law 5255/2025 (the Law), published on 28 November 2025, introduces a comprehensive set of amendments to Greek competition law, bringing national merger control procedures into closer alignment with the EU Merger Regulation (EUMR).
2. Notably, the Law removes the 30-day deadline for submitting a merger notification to the Hellenic Competition Commission (HCC), thereby harmonizing Greek practice with the EUMR. The reform also clarifies that the deadlines for the assessment of a notification will not start to run until the notification form is fully and correctly completed. 
3. This Briefing outlines the key changes introduced to Greek competition law, focusing on merger control procedures, increased sanctioning powers and use of technological tools.

B. Key Takeaways

1. Abolition of the 30-day Notification Deadline: The Law abolishes the 30-day notification requirement, in this way reconciling Greek merger procedure with the EUMR, which does not set a fixed deadline to notify after signature of the agreement. The amendment does not affect the obligation to notify transactions that meet the statutory thresholds pre-closing and does not remove the obligation to stand still pre-HCC clearance.
2. Non-Commencement of Deadlines Due to Incomplete or Incorrect Notifications: The statutory review periods will not begin if the notification form is incomplete or contains inaccuracies. Within seven working days of submission, the HCC may request the notifying parties to correct or complete the notification.
3. Non-Commencement of Deadlines Due to Misleading Information or Post-Notification Changes: Deadlines will also not commence where:
   1. the notification is incorrect or misleading and does not allow the HCC to evaluate the notified transaction, or
   2. the notifying parties inform the HCC of significant changes to the transaction post-notification or provide new information, which they should have included in their original filing and which may materially affect the HCC's review.
      
      The HCC must inform the parties within seven working days of becoming aware of these issues.
4. Increased Sanctioning Powers for Violations of Articles 38 and 39 of Law 3959/2011: In line with the ECN+ Directive (2019/1), the Law strengthens the HCC's sanctioning powers for procedural violations. The HCC may now impose fines of up to 1% of an undertaking's global turnover for failure to provide information and/or for obstruction of on-site inspections. This is in addition to the daily penalty imposed in cases of non-compliance with the HCC's request.
5. Introduction of New Article 38A - Use of Technology and AI Tools: A new Article 38A is introduced that authorizes the HCC to use advanced technological tools, including AI, to carry out its functions. The HCC may in particular use data mining systems and connect with public and private databases. The Law also grants the HCC direct access to the national electronic public procurement system (ESIDIS), strengthening its investigatory and data-analysis capabilities and enabling it to combat bid rigging in the field of public procurement.

C. Final Remarks

1. The Law marks a significant step in the continued modernization of Greek merger control, aimed at improving the standard of submissions and allowing for the more efficient assessment of notifications. 
2. Alignment with EU merger rules, as well as strengthening of the HCC's sanctioning and investigatory powers, through the provision for stricter penalties for procedural violations and the ability to use advanced technological tools, aims at greater procedural efficiency and effectiveness of enforcement.
3. For undertakings, these changes underscore the importance of preparing complete, accurate and robust merger notifications from the outset, as well as ensuring full cooperation during the review process. 
4. Overall, the Law is expected to streamline merger control proceedings, reduce procedural uncertainty and align the Greek practice with EU standards - contributing to a more predictable and effective enforcement environment.

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