The main index of the Greek bourse chalked up a weekly rise for the first time in five weeks yesterday, partly thanks to a positive session for small- and mid-caps. However, the threat of a fresh credit rating downgrade by Standard & Poor’s weighed on investor sentiment. The Athens Exchange (ATHEX) general index closed at 1,486.50 points, expanding 0.84 percent from Thursday’s close at 1,474.05 points. On a weekly basis the index climbed 3.47 percent. The blue chip FTSE/ATHEX 20 index grew by just 0.40 percent to end at 705.55 points, while the mid-cap FTSE/ATHEX 40 index perked up 1.40 percent and the small-cap FTSE/ATHEX 80 index jumped 2.66 percent. Blue chips outside the banking sector outperformed yesterday, led by OPAP (up 4.76 percent). Close behind were Marfin Investment Group (4.62 percent), Coca-Cola HBC (2.01 percent) and Motor Oil (1.72 percent). National Bank worried investors with its 2.19 percent decline, followed by Alpha Bank (down 1.35 percent) and ATEbank (1.19 percent). In total 119 stocks moved up, 54 went down and 41 remained unchanged. Forthnet led the gainers with a 23.91 percent rise, while Maritime of Lesvos posted the biggest loss with a 26.67 percent decline. Turnover came to 87.8 million euros, down from Thursday’s 151 million.