Stocks gained slightly yesterday on the Athens Stock Exchange, with investors concentrating on a few blue chips. The ASE general index closed at 3,123.46 points, a gain of 7.76 points or 0.25 percent. During the session, it had reached as high as 3,131.26 points. The FTSE/ASE-20 index of blue chips declined a small 0.05 percent to close at 1,750.59 points. Mid- and small-caps gained 0.24 percent and 0.40 percent, respectively. A few blue chips posted significant gains: They were refinery Hellenic Petroleum (up 2.61 percent to 9.44 euros), construction firm Hellenic Technodomiki (1.93 percent to 4.22 euros), Coca-Cola HBC (1.29 percent to a 52-week-high of 23.60 euros), betting company OPAP (1.14 percent to a 52-week-high of 24.80 euros), EFG Eurobank (1.07 percent to 26.34 euros) and casino and hotel operator Hyatt (1.06 percent to 9.50 euros). National Bank posted minor gains (0.34 percent to 29.18 euros). By contrast, Alpha Bank dropped 2.50 percent to close at 21.88 euros, Piraeus Bank and energy company PPC each declined 1.01 percent and Emporiki Bank declined 0.94 percent. Of 338 traded stocks, 148 gained, 126 declined and 64 ended unchanged. Turnover reached 174.32 million euros, including 10.5 million in prearranged trades.