Case C-746/21 P: Judgment of the Court (Third Chamber) of 9 November 2023 — Altice Group Lux Sàrl, previously New Altice Europe BV, in liquidation v European Commission, Council of the European Union (Appeal — Competition — Control of concentrations between undertakings — Regulation (EC) No 139/2004 — Plea of illegality — Article 4(1) — Prior notification obligation for concentrations — Article 7(1) — Concentration standstill obligation — Scope — Concept of the ‘implementation’ of a concentration — Article 14(2) — Decision imposing fines for implementing a concentration before its notification and clearance — Obligation to state reasons — Principle of proportionality