JEDDAH: Gulf and neighboring Arab stock markets plummeted across the board this week, coming under pressure from investors' downbeat reactions to annual results and political developments in Tunisia and Lebanon, financial analysts said Friday. However, they expected robust oil prices and results of petrochemical and related sectors to remain a key factor to keep regional markets buoyant. Saudi stocks also lost ground this week due to profit-taking despite the declaration by the market's leader, the Saudi Arabian Basic Industries Corp. (SABIC), that it had posted an increase in profits of 138 percent in 2010, to $5.76 billion. The Saudi stock benchmark Tadawul All Share Index shed 0.89 percent, closing the week at 6,657.78 points. However, Saudi analyst Mohammad Anqari predicted that SABIC and other petrochemical firms would spur the Saudi stock exchange through higher prices of petrochemical products that would lead to higher earnings later in 2011. "Stronger world demand for crude and petrochemical products will mean larger profits for SABIC and other petrochemical firms," he said, playing down expectations of lower profits for the banking sector due to toxic loans. "The allocations for bad loans will not be the main problem for the banking sector. The main issue for banks lies in their abundant liquidity and if they decide to expand lending," he said. Saudi Basic, the world's biggest petrochemicals maker, dropped the most in six months. Saudi Arabian Mining Co. decreased for a fourth day after it posted a fourth-quarter loss. The Tadawul All Share Index declined 0.9 percent, the most since Nov. 23, to 6,657.73 at the close. The measure has slipped 0.9 percent this week, snapping a seven-week rally. “There's a little disappointment that SABIC's numbers missed estimates,” said Haissam Arabi, chief executive officer of Gulfmena Alternative Investments in Dubai. The decline in Saudi shares “is a short-lived over- reaction to SABIC earnings considering the petrochemical cycle. The results triggered some profit-taking after a recent rally in the Saudi market,” he added. The Tadawul has risen 5.4 percent since the end of November. Elsewhere, Kuwait's KSE all-share index lost 0.58 percent this week, to close at 6,896 points. UAE shares also lost ground. The benchmarks of the Dubai and Abu Dhabi stock exchanges shed 0.97 percent and 1.4 percent, closing respectively at 1,609 points and 6,684 points. Jordanian shares were volatile, as investors resorted to profit- taking after last week's gains. The all-share price index of the Amman Stock Exchange lost 0.88 percent, closing at 2,447 points, the ASE weekly report said. Egypt's AGX 30 index plunged 6.4 percent, closing at an 11-week low of 6,698 points.