Commission Regulation (EC) No 1130/98 of 29 May 1998 derogating from Regulations (EEC) No 1589/87, (EEC) No 429/90, (EEC) No 1158/91, (EEC) No 3398/91 and (EC) No 2571/97 as regards the time limit set for submitting tenders for the month of August 1998