DMA compliance as a defence in EU merger control

The Digital Markets Act, which entered into force in March 2024, imposes a regulatory regime on designated digital gatekeepers. Although the DMA does not alter the substance of the EU Merger Regulation, it potentially affects the European Commission’s assessment of mergers involving those gatekeepers. This is because the DMA prohibits certain forms of potentially exclusionary conduct that have in the past been predicted to arise from vertical or conglomerate mergers. This article examines the legal framework applicable to the Commission’s assessment of non-horizontal mergers in light of the DMA. It explains that, absent evidence to the contrary, compliance with the DMA should create a legal presumption that designated gatekeepers will not engage in potentially exclusionary conduct of the kind regulated by the DMA.