The European Commission opened a preliminary review in March 2024 into whether Microsoft's €15M investment in Mistral AI constituted a reportable concentration under EU merger rules. Green MEPs called the deal a "Trojan horse" for Big Tech consolidation of the European AI sector — particularly given Mistral's prior role lobbying to soften EU AI Act regulations on foundation models. The EC ultimately concluded the deal did not meet merger notification thresholds but the episode highlighted tensions between European AI sovereignty and Big Tech investment.