Commission Regulation (EC) No 588/1999 of 18 March 1999 derogating from Regulations (EEC) No 1589/87, (EEC) No 429/90, (EEC) No 1158/91, (EEC) No 3378/91, (EEC) No 3398/91 and (EC) No 2571/97 as regards the time limit for the submission of tenders for May 1999