Greek stocks tumbled yesterday as selling pressure on National Bank rubbed off on other lenders, dragging the sector more than 7 percent lower. The Athens bourse benchmark general index fell 4.62 percent to 2,279.96 points, closing just above the session low of 2,270 points. Major European bourses were showing modest gains yesterday before turning mixed in late afternoon trade. National Bank slumped 10.69 percent to 18.30 euros after news of its share capital increase, while banks fell away by 7.48 percent. Eurobank lost 8.62 percent to 7.95 euros and Bank of Piraeus shed 6.25 percent to 7.50 euros. The blue chip FTSE/ATHEX 20 index dipped 5.21 percent to close at 1,159.58 points and the mid-cap FTSE/ATHEX 40 index dropped 4.28 percent. Turnover reached 322.4 million euros versus 176 million previously.