Greek stocks turned south after four consecutive winning sessions yesterday, amid a mildly positive climate on European bourses. Banks led blue chips into negative territory, with their sectoral index losing 0.82 percent. The Athens Stock Exchange (ASE) general index ended 0.41 percent lower at 4,064.03 points. The blue chip FTSE/ASE 20 shed 0.53 percent, the FTSE/ASE Mid-40 slid 0.40 percent and the FTSE/ASE Small-Cap 80 declined 0.57 percent. Among blue chips, Cosmote gained 1.64 percent, Titan was up 1.19 percent, Motor Oil rose 0.46 percent and OPAP added 0.37 percent. Alpha Bank edged up and Emporiki ended unchanged. In contrast, Piraeus Bank stumbled 2.23 percent lower and National Bank dropped 1.20 percent. Intracom shed 1.18 percent. Viohalco, ATEbank, Germanos, Hellenic Petroleum and OTE all ended lower. Media and raw materials led sectoral indices lower, with respective losses of 2.91 percent and 2.15 percent. Turnover was much thinner than in preceding sessions, totaling 284.53 million euros, of which 74.8 million was accounted for by banks National and Piraeus. Analysts said that if blue chips continue to lose steam, buying interest will be limited to selected stocks considered to be involved in business deals currently brewing.