Hijja 1431 H. / 9 November 2010, SPA -- U.S. inventories held at the wholesale level rose for a third consecutive month, the government reported Tuesday, offering mildly encouraging signs that the economic expansion will continue. However, the jump in wholesale inventories came as demand for goods failed to keep up with production, suggesting output will remain weak as wholesalers try to decrease stocks of unsold goods. Inventories surged a bigger-than-expected 1.5 percent in September, matching a July gain that was the biggest increase in more than two years, the Commerce Department said. Sales at the wholesale level rose 0.4 percent in September following a 0.5 percent gain in August. Inventories are a key component of changes in gross domestic product (GDP) over a business cycle, and rebuilding of merchandise levels from record low supplies has been a key driver of the U.S. economy's recovery from the worst recession since the 1930s.