Article 39 of the Digital Markets Act (DMA) contains specific provisions on the cooperation between the European Commission and national courts in the context of private enforcement. These rules draw inspiration from the experience gained under Regulation 1/2003 in the field of antitrust enforcement. The overarching aim is to ensure consistent application of the DMA and to safeguard the principle of loyal cooperation.
Below is a brief overview of the key elements:
Amicus Curiae Interventions
Under Article 39(3) DMA, the Commission may, on its own initiative, submit written observations to national courts. These observations aim to support the coherent interpretation and application of the Regulation. In addition, courts may permit the Commission to present oral observations. This is somewhat narrower than the equivalent provision in German law (Section 90(2) GWB), which also allows the Commission to speak and ask questions during hearings.
For the purpose of participating in civil proceedings, the Commission may request the transmission of all documents necessary to assess the case. National courts are obliged to comply and ensure the proper transmission of such documents. Importantly, this means that domestic procedural frameworks must accommodate the principle of loyal cooperation, for instance by not making the transmission conditional on the Commission’s prior registration with the national e‑filing system (e.g. EGVP in Germany).
Loyal Cooperation Obligations
Beyond the Amicus Curiae function, Article 39(1) and (2) DMA establish a broader framework for mutual assistance between national courts and the Commission:
- Under Article 39(1), national courts may request information or opinions from the Commission concerning the application of the DMA. This provision is closely linked to Article 39(5), which sets out the so-called “coherence mechanism”: national courts must not adopt decisions that run counter to decisions taken by the Commission. To prevent such inconsistencies, the Commission is encouraged to engage proactively and contribute its expertise to national proceedings.
- Conversely, Article 39(2) obliges Member States to transmit copies of any judgments applying the DMA to the Commission. This obligation applies regardless of whether the judgment was issued shortly after the DMA’s entry into force and must be fulfilled promptly upon delivery.
The Coherence Mechanism (Article 39(5) DMA)
Article 39(5) introduces a formal coherence rule: national courts must not take decisions that conflict with Commission decisions under the DMA. At first glance, this may appear to infringe the principle of separation of powers. However, the DMA provides that only the Commission is empowered to enforce the DMA administratively, subject to judicial review by the Court of Justice of the European Union (CJEU). This institutional design justifies the primacy of Commission decisions, particularly in relation to gatekeeper designations and violations of core obligations.
From a procedural perspective, the coherence rule strengthens the position of claimants in follow-on actions by granting binding effect to Commission findings on the underlying facts.
Importantly, the coherence obligation already applies once a decision is “adopted”—not only once it becomes final or enforceable. Even draft decisions that the Commission intends to adopt must be taken into account. In such cases, the national court may be required to suspend proceedings until the Commission finalises its position. That said, courts remain free to initiate preliminary ruling procedures under Article 267 TFEU.
Through these provisions, the DMA ensures a uniform European interpretation and application—particularly crucial in a legal environment shaped by platform-based ecosystems and cross-border market dynamics.
