European shares drifted lower on Wednesday after their biggest gain in more than four months in the previous session, with chemicals among the hardest hit after results from Syngenta, Reuters reported. At 0721 GMT, the FTSEurofirst 300 index of top European shares was down 0.2 percent at 1,051.32 points after surging 2 percent on Tuesday following firm demand at Spanish short-term debt sales. Investors were nowlooking forward to an auction of longer-dated debt on Thursday. \"After yesterday\'s Spanish (debt) auction, which went reasonably well, investors are positioning for another auction on Thursday which might be a little bit difficult,\" said Philippe Gijsels,\" head of research at BNP Paribas Fortis Global Markets in Brussels. \"You are in a situation where you fear that the euro zone problems might keep resurfacing. You have elections in France and Greece and Spain\'s economy is under pressure. The market could come down more in the coming weeks.\" Chemical shares were among the top decliners, led lower by the world\'s largest agrochemicals company, Syngenta, which fell 2.3 percent after posting in-line results.