The main index of the Greek bourse slipped to lows unseen since April 1997 yesterday, amid concerns about developments regarding Portugal and the eurozone in general, while soaring Greek bond yields did not help either. The Athens Exchange (ATHEX) general index closed at 1,354.63 points, contracting 2.60 percent from last Friday’s close at 1,390.84 points. The blue chip FTSE/ATHEX 20 index fell 3.50 percent to end at 624.51 points. Banks were particularly hard hit, with Eurobank EFG giving up 9.72 percent, Hellenic Postbank shedding 8.09 percent, Alpha Bank declining by 8.08 percent and National Bank dropping by 6.62 percent, while Marfin Investment Group lost 6.25 percent. The banks’ sectoral index gave up 6.56 percent. The only blue chips to head north were the OPAP gaming company (up 3.09 percent) and OTE telecom (0.74 percent). Public Power Corp and Coca-Cola Hellenic were non-movers. In total, 31 stocks moved up, 126 went down and 45 remained unchanged. Byte Computer led the gainers, jumping 10 percent, while furniture maker and retailer Sato posted the biggest loss with a 20 percent decline. Turnover came to 96.9 million euros.