Judgment of the General Court (First Chamber) of 11 December 2018.#BTB Holding Investments SA and Duferco Participations Holding SA v European Commission.#State aid — Steel industry — Aid granted by Belgium in favour of a number of undertakings in the iron and steel industry — Decision declaring that aid incompatible with the internal market and ordering its recovery — Obligation to state reasons — Concept of State aid — Advantage — Private investor test.#Case T-100/17.