AlQa'dah 24, 1433, Oct 10, 2012, SPA -- U.S. wholesale inventories rose as expected in August, while sales at wholesalers rose for the first time in four months, the government reported Wednesday. The Commerce Department said that wholesale inventories rose 0.5 percent in August to $487.5 billion, or 26.9 percent higher than the post-recession low seen in September 2009. Inventories rose 0.6 percent in July. Sales at the wholesale level jumped 0.9 percent in August, ending three months of declines. The sales increase was the biggest one-month gain since February and was nearly double the 0.5 percent gain expected by economists. Sales gains were widespread but led by a 5.6 percent jump in petroleum sales and a 2 percent increase in auto sales. Companies typically increase their inventories when they expect sales will rise in coming months. Faster restocking helps drive economic growth, because when businesses order more goods, it leads to more factory production. Inventories are a key element in the government's measure of changes in gross domestic product (GDP) and can highlight underlying strength or weakness in U.S. growth. Growth has slowed this year, partly because high unemployment and weak pay increases have caused U.S. consumers to spend less. Weaker global growth also has dampened demand for U.S. exports. Many economists believe U.S. economic growth has hovered near a 2 percent annual rate during the July-September quarter, which would be a slight improvement from the weak 1.3 percent annual growth rate recorded in the April-June quarter.