Stocks gained yesterday on the Athens Stock Exchange, as investors went after certain blue chips, especially National Bank. The ASE composite share index closed at 4,781.39 points, a gain of 18.47 points or 0.39 percent. On a weekly basis, it gained 1.24 percent, boosting this year’s gains to 8.81 percent. The FTSE/Athex 20 index of blue chips gained 0.49 percent to close at 2,596.01 points. Mid-caps declined 0.13 percent and small-caps gained 0.10 percent. The FTSE/Athex International gained 0.41 percent, closing at 6,856.21 points. Ten of the 17 sectoral indices declined. The top gainers were telecommunications (up 1.82 percent), personal and household goods (0.87 percent), and industrial goods and services (0.63 percent). The top losers were construction and materials (down 1.47 percent), utilities (1.41 percent), technology (0.92 percent) and media (0.92 percent). Among blue chips, the top gainers were Bank of Cyprus (higher 2.37 percent to -12.10), oil refiner Motor Oil (2.33 percent to -21.08), metals group Viohalco (2.13 percent to -10.56), mobile telecommunications company Cosmote (2.04 percent to -23.06) and telecoms firm OTE (1.75 percent to -22.06). National Bank gained 1.25 percent to close at an all-time high of -41.98. Turnover reached -707.42 million, including -282.38 million in prearranged trades.