A Belgian Call-In Proposal: Joining the EU Trend, But Questions Remain

A contribution from William Wulff*

I. A Belgian step into the Call-in arena: breaking news from the BCA

In a surprising yet timely announcement, the President of the Belgian Competition Authority (BCA), M. Axel Desmedt, revealed late on LinkedIn on Thursday, 17/04/2025, for now only available in Dutch, his proposal for Belgium to move toward introducing a national call-in power.^[1] While details remain scarce, this move signals that the country is ready to follow a path already taken by several of its direct EU neighbours to tackle below-threshold mergers with potentially harmful effects on competition.

The absence of a standalone call-in mechanism has been limiting the Kingdom’s ability to tackle the so-called “Killer acquisitions”^[2] (Acquisition of a start-up or a company with high innovation potential that generates little or no turnover by a large company, usually in the tech, energy or pharma sectors^[3])^[4] and “Buy-and-Build” (strategy in which companies gradually buy up smaller competitors in order to consolidate their market share in a specific market and can thus force higher prices, situation mostly seen in niche markets, as in Finland, where it was seen in the veterinary sector^[5]).

Until now, Belgium’s approach to sub-threshold acquisitions relied primarily on the Towercast doctrine^[6], which allows competition authorities (NCA) and courts to review acquisitions by dominant entities under abuse of dominance rules, if those acquisitions are not notifiable under EU or national merger control laws.

Belgium was actually the most proactive with this technique as it launched the first investigation under that basis only one week after its rendering by the Court.^[7] However, this legal avenue has proven limited in practice, as the President’s note notices. In fact, the two merger cases (Proximus/EDPnet^[8] & Dossche Mills/Ceres^[9]) where the BCA considered intervening were ultimately abandoned or divested by the parties before any decision was reached^[10].

The fact that this announcement came directly from the BCA’s leadership, and in such an informal and urgent medium on social media, illustrates the political weight and urgency behind this shift. Belgium is catching up, and sending a strong message.

II. What are Call-in Powers?

Call-in powers refer to discretionary tools granted to competition authorities allowing them to examine mergers or acquisitions that fall below traditional notification thresholds, usually based on turnover. These mechanisms are designed to capture transactions that may nonetheless pose significant risks to market competition. In the latest developments, they are particularly aimed in examining cases involving start-ups, innovators, or nascent competitors. Depending on the National provision, that capture can be done ex-ante or ex-post of the merger implementation.

These mechanisms have gained increasing prominence in recent years, particularly after the European Commission’s revised 2021 guidance on Article 22 EUMR, which temporarily served as a de facto EU-level call-in. And especially since the Court’s judgment in Illumina/Grail^[11], which rejected the same expansive interpretation of Art. 22 EUMR and restricting the referral of cases from NCAs to the Commission to situations where the NCA is competent to review the concentration under its national merger control law.

Since then, several Member States have begun to develop their own frameworks to close the enforcement gap exposed by the Illumina/Grail case, pushed and envigored by an explicit Commission endorsement^[12].

Unlike the traditional turnover-based merger control systems, which rely on clear and predictable quantitative thresholds, call-in powers are typically grounded in qualitative criteria — such as the potential impact of a transaction on competition, innovation, or market structure. These mechanisms often incorporate a “local nexus” requirement to ensure national relevance, and are usually subject to strict time limits aimed at preserving legal certainty.

This problematic of uncertainty is exacerbated by the significant national divergences in their design across the Member States, far from the streamlined and harmonized turnover-based regimes normally prevalent across the EU.

A common approach, seen for instance in Denmark^[13], Hungary^[14], Italy^[15], Sweden^[16], and in the Czech Republic’s^[17]pending reform, is to introduce an additional threshold based on the combined domestic turnover of the parties. This ensures that transactions involving a low- or zero-revenue target, often a start-up, can still be captured if the buyer is sufficiently large and has a developed activity nationally.

Other jurisdictions, such as Latvia^[18] and Slovenia^[19], have opted for a market share-based threshold, whereby concentrations can be reviewed if the parties exceed a certain percentage of market control, regardless of turnover.

In addition, some Member States have adopted (or proposed) more discretionary frameworks, granting broad investigative latitude to their competition authorities. This is notably the case in Ireland^[20], Lithuania^[21], and in the proposed legislative reform in Luxembourg^[22].

Last but certainly not least, the specific possibility of a ministerial decision that only exists in Cypriot law where the Minister for Energy, Trade and Industry^[23] can call-in mergers of “major importance” trough one decision. This intriguing provision where thoughts of arbitrariness and procedural safeguards come straight to mind exists also in the proposed called-in Luxemburgish Law^[24] with cleared details in relation to its enforcement.

Graphic that illustrates the call-ins-powers in the EU and the EEA

Call-in powers, in our opinion, differ from traditional merger control in that they prioritize flexibility over predictability. While this makes them effective in catching harmful concentrations that would otherwise escape scrutiny, such as so-called killer acquisitions, it also introduces challenges in terms of legal certainty for merging parties. Firms may be unaware that their transaction could fall within the scope of scrutiny of a Member State with such provision, leading to unpredictability and increased compliance costs.

III. A European trend gaining traction: France, the Netherlands, Czechia, Slovakia…

The Belgian decision comes at a strategic moment in the European landscape. Just a month ago (10/04/2025), France emitted the result of its public consultation on “Mergers below the control thresholds” on whether to introduce a national call-in system.^[25]

Meanwhile, the Netherlands, after long pleadings by the Chairman of the Autoriteit Consument en Markt (ACM) Martijn Snoep on its blog, has recently confirmed (March 2025) its intention to adopt a similar instrument through a bill presented by two representatives along their explanatory memorandum^[26], adding to a wave of reforms across the continent^[27].

These national initiatives are not isolated. Rather, they reflect a shared effort to capture mergers that fall below existing jurisdictional thresholds, particularly in digital and pharmaceutical markets, where turnover often fails to reflect the strategic or competitive value of a target. Countries like Ireland (in force since 27/09/2023), Italy (in force since 27/08/2022) and Denmark (in force since 1/07/2024) have been the latest to incorporate in their national provision.
Other countries wait since long for the introduction, the Czech authority hopes that its proposal will pass. If it fails, it will resubmit it in the next legislative term. There are talks and rumors of its development in Slovakia without any publication.^[28]

Italy was the first country to make use of its call-in power to send a referral of a concentration falling below thresholds. This referral was accepted, and the concentration ultimately cleared. Still Nvidia brought that clearance decision before the General Court^[29] as it considers that the decision is incompatible with „article 22 legislative history, context and intended object“ and that this exercise of the call-in is „loosely defined, ex post, discretionary call-in powers„.^[30] Italy has also been the most active user of its newfound tool, with 9 uses in less than 3 years, since its introduction in in August 2022.

Among longer-standing regimes, Sweden and Lithuania, despite having call-in systems for over two decades (since 2004), have used them sparingly, with seven and four cases respectively. Slovenia has applied the mechanism twice. In contrast, Italy has been notably proactive to use its newly given powers, invoking its call-in powers nine times. Meanwhile, other newer adopters like Ireland and Denmark have yet to deploy the tool, suggesting a cautious approach despite its availability.^[31]

Three patterns emerge from this data.

First, early adopters (Cyprus, Lithuania, Sweden) have used the instrument infrequently, even after decades of availability.
Second, some newer jurisdictions, particularly Italy, have embraced the tool enthusiastically.
Third, others (Ireland, Denmark) appear to be exercising restraint, possibly awaiting transactions with clear competitive risks before intervening

This whole momentum by States like Italy is not coincidental. It is the direct consequence of the Court of Justice’s 2024 ruling in Illumina/Grail, which limited the European Commission’s ability to accept referrals under Article 22 EUMR from national authorities that lack jurisdiction under their own laws. In short, Member States must now build their own tools if they want to catch potentially problematic mergers and refer them upward.

IV. Call-in powers as a popular fix: promise vs. pitfalls

In this context, call-in powers are increasingly seen as the solution of choice. They offer national authorities the flexibility to intervene in concentrations that would otherwise escape scrutiny, particularly “Killer acquisitions” and “buy-and-build” strategies involving nascent competitors or innovative startups. The idea is simple: if traditional turnover thresholds fail to capture economic reality, discretionary intervention should fill the gap.

However, this flexibility comes at a cost. Legal certainty for merging parties remains a major concern. Unlike traditional merger regimes, which rely on fixed thresholds and procedural safeguards, call-in powers are often discretionary, subject to qualitative criteria, and vary (as stated) widely between jurisdictions.

This creates uncertainty for companies, especially in cross-border transactions. In the absence of clear and harmonised criteria in a member state, this could lead to significant legal costs on one side, in particular, lawyers‘ fees for analysing the applicable national laws in the light of the call-in rules, as well as those relating to the preparation and filing of notifications. Consequently, the costs associated with legal compliance applicable across all jurisdictions where activities may happen, may rise considerably. On the other side, timeframes for the mergers may be impacted at several levels: the time needed for the advisers to gather information and finalise the notification, but also the potentially long wait for the decision of the national competition authorities. The worst case scenario for merging parties is to have to implement structural remedies and divest their transaction in an already implemented merger due to an ex-post call-in.

Finally, the synergy between national call-in regimes and Article 22 EUMR remains unproven. The Belgian move, like those in Ireland or Denmark, but most especially the Italian approach may facilitate future referrals to the Commission, but only if those systems are properly designed and consistently applied.

As long as the Nvidia/Run:Ai case remains pending before the General Court, there is no clarity on how referrals based on national call-ins will be treated at the EU level. That case could determine the legal boundaries of such strategies and their compatibility with the Merger Regulation.

Notably, Germany has firmly rejected the introduction of a call-in mechanism in its national competition law, citing precisely this lack of legal clarity. For the Bundeskartellamt, predictability for companies outweighs the potential gains of an expanded enforcement toolkit. They prefer to expand on their very own tool (that they share with Austria); the Value-based threshold, supposed to represent the effective value of a merger with a party having little or no turnover.^[32]

V. Conclusion: A strong signal, but not a silver bullet

The BCA’s President’s announcement marks a significant shift in the country’s competition enforcement framework. It sends a clear message that the BCA is willing to step up its scrutiny of below-threshold mergers, especially in sectors where innovation and market dynamics evolve rapidly. It also aligns Belgium with a growing European movement towards a more discretionary, risk-based merger control. It might also show the first crack of the Towercast doctrine, a tool filled with hope who fell short from its expected results. We only have to see what future holds: a public consultation, a legislative proposal?

But the real test lies ahead. If Belgium adopts such a mechanism, its design will determine both its impact and its consistency with the EU framework. Will the Belgian legislature provide clear criteria, procedural safeguards, and guidance? Will businesses be able to anticipate whether their transaction may fall within the scope? Will the system facilitate or complicate cooperation with the European Commission under Article 22 EUMR?

Until these questions are answered, and until the General Court clarifies the boundaries of a referral under Art. 22 EUMR on the basis of a call-in as in Nvidia/Run:ai, legal uncertainty will persist. For merging parties, the challenge remains the same: to navigate a fragmented and evolving regulatory landscape, with no clear map in sight.

*William Wulff holds a Master degree in Belgian Law with a European specialization for UClouvain (Belgium). He is an alumnus of the Europa-Institut and is currently a PhD student at the JMU-Würzburg in EU Competition Law.

^[1] https://www.linkedin.com/posts/axel-desmedt-57a9715_nota-call-in-activity-7318688083053350914-Tztk?utm_source=share&utm_medium=member_desktop&rcm=ACoAADuB_icBBVZOtJqna-JDys9WZPCKKsG6d8w.

^[2] OECD (2020), Start-ups, Killer Acquisitions and Merger Control.

^[3] Lear for the European Commission, Ex-post evaluation: EU competition enforcement and acquisitions of innovative competitors in the pharma sector leading to the discontinuation of overlapping drug research and development projects, November 2024.

^[4] Colleen Cunningham/Florian Ederer/Song Ma, “Killer Acquisitions”, Journal of Political Economy, Vol. 129, No. 3, pp. 649–702.

^[5] Rashid Baxter, Finland pushes for call-in powers to tackle PE-backed vet sector concentration.

^[6] CJEU, C-449/21 – Towercast, ECLI:EU:C:2023:207.

^[7] Friso Bostoen, ‘Reviewing Mergers Under Article 102 TFEU: Proximus/EDPnet (Belgium)’ (2024) 15 Journal of European Competition Law & Practice 258, 258.

^[8] Belgian Competition Authority, ‘Press release n°10/2023 – The Belgian Competition Authority opens an ex officio investigation into a possible abuse of dominance by Proximus in the context of the takeover of edpnet, in application of the Towercast case law’.

^[9] Belgian Competition Authority, ‘Press Release N°3/2025 – The Belgian Competition Authority Opens Ex-Ante Proceedings into the Possible Anti-Competitive Effects of Dossche Mills’ Proposed Takeover of Ceres’ Artisan Flour Business’.

^[10] Van Bael & Bellis, “Belgian Competition Authority Again Stops Below-Threshold Merger on Basis of Antitrust Rules Rather Than Merger Control Provisions”.

^[11] CJEU, Joined Cases C-611/22 P, C-625/22 P – Illumina v Commission, ECLI:EU:C:2024:677, para. 222.

^[12] Margrethe Vestager, ‘Speech by EVP M. Vestager at the 28th Annual Competition Conference of the International Bar Association.

^[13] Section 12(6) of the Danish Competition Act.

^[14] Article 24(4) of Act LVII of 1996 on the Prohibition of Unfair and Restrictive Market Practices.

^[15] Article 16(1) of the Italian Competition Act (No. 287/1990).

^[16] Section 7 of the Swedish Competition Act (2008:579).

^[17] Section 13a of the amended Zákon č. 143/2001.

^[18] Section 15(2¹) of the Latvian „Competition Law“ (Konkurences likums).

^[19] Art. 66(3) of the Prevention of Restriction of Competition Act (Slovenian: Zakon o preprečevanju omejevanja konkurence (ZPOmK-2a).