Judgment of the Court of First Instance of 12 July 2001 in Joined Cases T-12/99 and T-63/99 UK Coal plc v Commission of the European Communities (ECSC Treaty — Decision No 3632/93/ECSC — Operating aid and aid for the reduction of activity — Authorisation ex post facto of aid already paid — Improvement of the viability of recipient undertakings — Degression of aid — Bonus paid to underground mineworkers (Bergmannsprämie) — Amendment of a modernisation, rationalisation and restructuring plan — Taking account of a concentration between undertakings — Statement of reasons)