Judgment of the General Court (Fourth Chamber) of 26 February 2019.#Athletic Club v European Commission.#State aid — Aid granted by the Spanish authorities to certain professional football clubs — Preferential tax rate on the income of the clubs authorised to operate as non-profit organisations — Decision declaring that the aid is incompatible with the internal market — Action for annulment — Interest in bringing proceedings — Admissibility — Infra-State measure — Selective nature — Distortion of competition — Effect on trade between Member States — Alteration to existing aid