For a third straight week stock markets remained under pressure from growing jitters from the US subprime mortgage crisis. Even though Greek banks are said to have limited exposure to such funds, the fear of shrinking liquidity remains strong and is creating a domino sales effect. The Athens Exchange (ATHEX) has lost about 10 percent, or -15 billion, of its total market value over the last three weeks. From the high of 5,136 points, reached on July 20, the general index fell to below 4,700 points on Friday, after losing 4.28 percent in the week, with intensified pressures in the last two trading sessions. Metals group Viohalco has led blue chip decliners in the three weeks, losing an accumulated 25 percent. Postal Savings Bank has followed, 22 percent down; Titan Cement, 20 percent; Public Power Corporation, 17 percent; Hellenic Technodomiki,16.5 percent; Motor Oil, 16 percent; Hellenic Petroleum, 15 percent; Bank of Cyprus, 14 percent and National Bank, 10 percent. OTE telecom and Coca-Cola HBC were the only blue chips to buck the trend. All sectoral indices but telecoms headed south, led by technology (down 9.70 percent) and media (9.65 percent). Commerce lost 9.17 percent, while industrial products and services, construction and financial services all shed more than 7 percent. Banks were 5.30 percent leaner. Responding to fears of a liquidity crisis, the European Central Bank on Thursday injected a further -61.05 billion into the market after an initial -94.84 million did not prove soothing enough. Analysts fear that a deterioration of the crisis, combined with the lack of shock absorbers, could lead markets even lower before the momentum is spent.