Commission Regulation (EEC) No 653/76 of 24 March 1976 amending the Annexes to Regulations (EEC) No 136/76, (EEC) No 336/76 and (EEC) No 638/76 fixing, pursuant to the invitation to tender opened by Regulations (EEC) No 3354/75, (EEC) No 135/76 and (EEC) No 357/76, the minimum selling price for skimmed-milk powder