Gulf stock markets plummeted across the board this week under pressure from global markets slump, uncertainty over world recovery and negative predictions about second-quarter results, financial analysts said Friday. They also attributed the plunge of Middle East bourses to the failure of the G20 summit in Toronto to give a hand to the faltering world economy and to volatile oil prices. Saudi shares deepened losses this week with the petrochemical sector leading the downward pressure due to bad news from the world's major economies. The Tadawul All Share Index (TASI) of the Arab world's largest bourse tumbled 3.94 percent this week, closing at 6,093.76 points. The Saudi stock exchange apparently reacted negatively to the G20 summit which “failed to develop immunity for the world financial system,” Jeddah-based Saudi analyst Yassin Jafri said. “Over the past weeks, the entire world has been watching a new financial collapse due to the European sovereign debt problem,” he added. However, Jafri expected Saudi stocks to pick up, thanks to the Kingdom's strong macroecomic indicators. The United Arab Emirates shares also plummeted this week amid growing doubts over the repayment of Dubai World debts, analysts said. The benchmarks of the Dubai and Abu Dhabi stock exchanges tumbled 4.48 percent and 1.72 percent, to close respectively at 1,470 points and 2,510 points. The Saudi stock exchange sank 10.42 percent in the second quarter, Dubai 20.7 percent, Abu Dhabi 13.56 per cent, Kuwait 13.22 percent and Egypt 11.36 percent. Kuwait's KSE all-share index also plunged 2.92 per cent to close at 6,432 points amid a hectic sell-off that involved all sectors, including blue chips. The weekly report of the Kuwait Financial Centre attributed the decline mainly to the sluggish performance of the country's business sector. Nasdaq Dubai, the only stock market in the Middle East with international acceptable standards. At Nasdaq Dubai, shares of Dubai Ports World lost 3.41 percent, closing at $0.425. The port operator still suffered from its decision to postpone a planned dual listing in London to 2011. With the holiday season starting, trading activities at the local Dubai Financial Market (DFM) more than halved.