France: Too small to notify, too dangerous to ignore? The French Competition Authority scrutiny of below-threshold acquisitions

The end of 2025 was marked by a novel and particularly noteworthy position taken by the French Competition Authority (FCA), in its Doctolib decision, demonstrating a readiness to scrutinise and sanction potentially anticompetitive acquisitions, even where they fall below merger control thresholds.
In Towercast judgment (C-449/21), the FCA issued its first-ever sanction for a below-threshold “killer acquisition,” relying on Article 102 TFEU to challenge an acquisition completed more than six years earlier and falling outside merger control notification requirements. This enforcement action follows an earlier, ultimately unsuccessful, attempt by the FCA to scrutinise a series of acquisitions ex post under Article 101 TFEU in the SARIA case, and this approach is further reflected in its ongoing public consultation on potential reforms of French merger control thresholds.

For companies, particularly those potentially holding strong market positions, the long-standing assumption that sub-threshold transactions would escape scrutiny can no longer be relied upon. Vigilance has now become indispensable in the French merger control landscape.

The Doctolib decision: abuse of dominance through strategic acquisition

Following a complaint by a competitor and subsequent dawn raid, the FCA investigated the 2018 acquisition of MonDocteur by Doctolib (a French leading platform for booking medical appointments and teleconsultations) under antitrust rules, as the acquisition was not subject to merger control. In November 2025, the FCA fined Doctolib a symbolic €50,000 for the predatory acquisition (whilst the total sanction amounted to approximately €4.7 million for other abuse of dominance practices). 

In setting the EUR 50,000 fine, the FCA expressly took into account that the conduct predated the 2023 Towercast judgment, at a time when the applicable legal framework was still unsettled.

The modest level of the financial penalty should not, however, obscure the significance of the decision. By clarifying the applicable legal framework and clearly signaling its enforcement intent, the FCA has created deterrent effects that extend well beyond the individual sanction imposed. Should the FCA apply its standard fining guidelines in future cases, financial penalties could be significantly higher, reflecting both the seriousness of predatory acquisitions and the duration of the infringement. In addition, the FCA could, in principle, order structural remedies such as divestments or demergers, although the implementation of such measures several years after closing would raise considerable practical and legal challenges.

The FCA followed a three-pronged legal test as follows.

1.  Pre-acquisition positions of the parties

The FCA first established Doctolib's dominant position, then relied heavily on its internal documents demonstrating that MonDocteur was perceived as its closest competitor with strong expansion potential in subsequent years. The French Authority emphasised the strong indirect network effects that characterise the market of online appointments, which reinforced barriers to entry and expansion, making competitive responses by rivals unlikely.

This analysis reveals the economic rigour underpinning the decision. The FCA's emphasis on MonDocteur's "potential" rather than its actual market position signals a forward-looking, dynamic approach to competitive assessment aligned with contemporary concerns about digital market concentration.

2. Rationale and strategic intent behind the acquisition

The FCA considered that Doctolib’s intent was to remove one of the main competitors and strengthen Doctolib's market position. It relied on incriminating internal documents confirming a desire to "kill competition" and the fact that value creation was “not the addition of the MD [MonDocteur] asset but its disappearance as a competitor, with immediate gains for some”.

References to "eliminating competition", "killing" rival products, or "locking" markets were considered decisive evidence of exclusionary intent. 

3. Actual effects of the practice

The FCA established anticompetitive effects by examining: (i) the evolution of Doctolib and its remaining “competitors"' positions post-transaction; (ii) changes in the economic model of healthcare professionals; (iii) Doctolib's ability to increase prices without losing customers, and to continue growing market share; and (iv) the broader impact on innovation and development of new technologies in the sector.

It considered that the acquisition significantly stifled competition by eliminating the only competitor capable of competing with Doctolib.

Such ex post review benefits from the advantage of hindsight, allowing the FCA to observe actual market developments rather than merely predict them, as would be required in ex ante merger control. 

A fundamental shift in risk assessment

This decision fundamentally alters risk assessment for dominant firms. Traditional turnover thresholds no longer constitute an invincible safe harbour. Acquisitions of small or emerging competitors may now trigger enforcement under Article 102 TFEU, irrespective of whether notification thresholds are met.

Ex-post antitrust scrutiny of below-threshold transactions is now a concrete risk that should be factored into merger planning, with early consideration of dominant position being essential.

The FCA’s approach in the Doctolib decision raises fundamental questions about the interaction between ex post antitrust enforcement under Articles 101 and 102 TFEU and traditional ex ante merger control, and clearly undermines legal certainty.

These issues warrant careful consideration as European competition law seeks to strike an appropriate balance between effective enforcement and legal predictability. 

The Doctolib decision also comes at a time when reforms to the French merger control regime could be expected, following the FCA’s launch of a public consultation on potential revisions to its merger control framework. The options currently envisaged by the FCA - namely (i) the introduction of a targeted call-in power, (ii) a mandatory notification obligation for designated undertakings, or (iii) exclusive reliance on ex post control, each raise distinct and significant legal and practical concerns.

Practical compliance takeaways

The combination of the Doctolib decision and the FCA's consultation reflects clear determination to close perceived enforcement gaps. Whether this results in new procedural tools or a more aggressive application of existing antitrust rules remains to be seen.

What is already clear is that:

• Below-threshold acquisitions by dominant firms now carry real enforcement risk.
• Transaction planning, documentation and internal communications require heightened discipline.
• Legal certainty has diminished, requiring more sophisticated antitrust analysis well beyond threshold calculations.
• Divergence between national regimes may increase if France adopts call-in powers or designation-based thresholds.
• The interaction between ex ante and ex-post enforcement mechanisms requires clearer delineation to avoid regulatory overreach whilst ensuring effective enforcement.

For general counsel and compliance teams, the message is unequivocal: merger control analysis can no longer stop at jurisdictional thresholds. A substantive competition assessment, focused on market power, competitive dynamics and strategic intent, has become indispensable, even for transactions that once appeared safely below the radar. This must be coupled with strict discipline over internal and transactional documentation, as documents created in the course of a deal may later be relied upon by competition authorities as evidence of anticompetitive intent or effects.

If you need more information or further guidance in this area, please contact Elsa Mandel Benichou or Thomas Oster.

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