Business & Finance Club - Riyadh : Saudi Arabian shares lost the most in three weeks, led by petrochemical companies, after oil fell on signs that fuel demand in the U.S. and China is faltering as the economic recovery slows.

Saudi Basic Industries Corp., the world’s biggest petrochemical maker, fell 1.7 percent and its unit Saudi Arabian Fertilizer Co. retreated the most in a month. The 143-company Tadawul All Share Index declined 0.9 percent, the most since July 20, to 6,264.01 at the 3:30 p.m. close in Riyadh. The Bloomberg GCC 200 Index of Gulf stocks slipped 0.4 percent. Crude oil, up 5.5 percent this quarter, lost 2.1 percent to $79.74 a barrel at 5:11 p.m. in the Saudi capital. The kingdom holds one-fifth of the world’s proven oil reserves.

“There has been a change in sentiment in petrochemicals following disappointing U.S. economic data and data on Chinese imports,” said Amro Halwani, a trader at Shuaa Capital PSC in Saudi Arabia. The recent rally in crude “may be losing traction as investors remain cautious and await word on tonight’s Fed announcement.”.

A U.S. report Aug. 6 showed private employers added 71,000 jobs in July, below the 90,000 median estimate in a Bloomberg News survey. China’s crude imports slumped 15 percent in July from June, preliminary government data showed. A U.S. government report tomorrow is likely to show that gasoline inventories remain near their highest in six weeks, according to a Bloomberg survey. China and the U.S. are the world’s biggest energy consumers.

The Federal Open Market Committee in the U.S. plans to announce its interest rate decision at 2:15 p.m. in Washington. Options outlined last month by Fed Chairman Ben S. Bernanke include providing more information about the Fed’s pledge to maintain record-low interest rates, reducing the rate it pays on banks’ reserve deposits and sustaining or expanding the size of the balance sheet.

Stocks Drop

The MSCI Emerging Markets Index lost as much as 1.2 percent, declining from a 14-week high. Stocks in Asia and Europe also fell and U.S. index futures declined.

Sabic retreated the most since July 26 to 87.50 riyals. Safco declined 1.3 percent, the most since July 10, to 137.25 riyals.

Dubai’s DFM General Index slipped 0.3 percent and Abu Dhabi’s ADX General Index fell 0.1 percent. Kuwait’s SE Price Index and Qatar’s QE Index advanced 0.1 percent. Oman’s MSM 30 Index was little changed and Bahrain’s gauge climbed 0.5 percent to the highest since June 24.