The Dutch legislature has advanced a bill amending the Competition Act to grant the Authority for Consumers and Markets (ACM) new powers to review certain mergers falling below existing notification thresholds, addressing concerns around serial and so‑called “killer” acquisitions.

Under the current Dutch merger control regime, concentrations are subject to mandatory notification only if the statutory turnover thresholds in Article 29 of the Competition Act are met. This framework has increasingly been viewed, by the ACM, as insufficient to address competition concerns arising from a series of smaller acquisitions (i.e., roll-up strategies), local or regional transactions, or acquisitions of innovative targets with limited turnover (i.e., so called "killer" acquisitions).

Against this background, the ACM has in recent years been increasingly vocal about what it considers to be the risks associated with so‑called “bead‑stringing” strategies and other acquisitions that may escape ex ante review but nevertheless lead to significant market power. The ACM has already taken a leading position at European level in its substantive assessment of serial acquisitions. In particular, on 21 February 2025, the ACM approved the proposed acquisition by pallet seller Foresco of competitors Vierhouten Palletindustrie and De With Pallets, explicitly applying a “stringing beads” theory of harm as part of its (in-depth) competitive assessment. This marked the first occasion on which a competition authority formally relied on such a theory to assess whether a series of acquisitions could cumulatively lead to the creation or strengthening of a dominant position.  The ACM has also demonstrated its willingness to scrutinise non‑notifiable transactions ex post under the abuse of dominance rules, including in its ongoing investigation into the acquisition of Ziemann by Brink’s.

The legislative proposal draws on developments at EU level and in other Member States, where national competition authorities have, since the ECJ ruling in Illumina/Grail, been granted call‑in or invocation powers to review non‑notifiable transactions. It also responds to limitations identified following the Court of Justice’s Towercast judgment, which allows for ex post intervention under abuse of dominance rules but offers limited legal certainty and remedial effectiveness.

Key elements of the proposed call‑in power

The bill introduces a new Section 5 to Chapter 5 of the Competition Act (Articles 49a–49d), creating a targeted call‑in mechanism for concentrations that fall below the existing turnover thresholds. Under the proposal, the ACM may require information and potentially impose a notification obligation where:

• the concentration does not meet the existing turnover thresholds; and
• at least one of the undertakings involved achieved turnover in the Netherlands of at least EUR 30 million in the preceding calendar year; and
• the ACM has reason to believe that the concentration could significantly impede effective competition in the Netherlands or a part thereof, in particular through the creation or strengthening of a dominant position.

The ACM must initiate the call‑in process within four weeks of the earliest of: (i) the public announcement of the transaction; (ii) the ACM becoming aware of it; or (iii) six months after implementation. Where the ACM imposes a notification obligation, a standstill obligation applies for transactions that have not yet been implemented. For transactions that have already been completed, the ACM may still require notification and, in certain circumstances, order the unwinding of the transaction if clearance is not obtained.

Implications for businesses and investors

If adopted, the new regime would expand the scope of Dutch merger control beyond the current bright‑line thresholds, particularly affecting larger undertakings pursuing acquisition strategies in local, regional or innovation‑driven markets. While the inclusion of a single party EUR 30 million turnover threshold is intended to limit legal uncertainty and to exclude transactions between smaller parties, companies may nevertheless face increased scrutiny of acquisition pipelines that previously fell outside mandatory review.

Based on the ACM’s previous sector studies, enforcement reports and public statements, certain sectors are likely to be among the first in which the call‑in power could be deployed in practice. The ACM has repeatedly expressed concerns about consolidation strategies in veterinary services and childcare, where it has in the past conducted market studies. Beyond these sectors, the ACM has explicitly identified a broader range of markets in which similar concerns may arise. These include auto‑repair shops, general practitioners’ practices, accountancy firms, insurance, software, and niche markets such as specialist hobby or food products, particularly where acquisitions are concentrated geographically or involve narrowly defined product markets.

The proposal also envisages that the ACM will publish guidance and allow for voluntary early disclosure, with a view to providing greater predictability as to when call‑in powers may be exercised. Substantively, any transaction that is called in would be assessed under the same “significant impediment to effective competition” test as applies under existing Dutch merger control.

Looking ahead

The bill has been amended following advice from the Council of State and is proceeding through the legislative process. Its entry into force would be determined by Royal Decree. If enacted, the Netherlands would join a growing number of jurisdictions, including Italy, Sweden, Denmark and Ireland, that have equipped competition authorities with tools to address perceived enforcement gaps in relation to below‑threshold transactions.