NEW YORK - August 16, 2011 - Walmart, the biggest U.S. retailer by revenues, warned on Tuesday that persistent weakness in the U.S. economy was putting pressure on its low income consumers who are increasingly worried about unemployment and becoming more reliant on government assistance.

The struggling U.S. economy is continuing to take its toll on Walmart’s domestic sales, as it reported its ninth consecutive quarter of falling sales at U.S. stores open for at least a year. Comparable store sales at Walmart in the U.S., excluding fuel sales and purchases at Sam’s Club stores, were down by 0.9% from a year ago.

“We remain concerned about the economic pressure on our customers and the uncertain impact it can have on their shopping behavior,” said Bill Simon, chief executive of Walmart’s U.S. business. “With this volatility, it is as important as ever to deliver on Walmart’s one-stop shopping promise for broad assortment and everyday low prices.”

Walmart, regarded as a bellwether for the U.S. economy, has been trying to improve its domestic performance after more than two years of stagnant same-store sales. Once revered for its “everyday low prices”, dollar stores and Amazon.com have been eating into Walmart’s market share and convincing consumers that they offer better bargains.

In spite of that disappointing stretch, analysts were heartened by signs that sales could soon turn around, as Walmart looks to reassert itself as the retailer with the lowest prices. Shares of Walmart rose 3.64% to $51.80 in mid-morning trading, as its results exceeded analysts’ expectations.

“Theoretically, this is a period when Walmart should be thriving,” said Brian Sozzi, retail analyst at Wall Street Strategies. “They have signalled that in the back half of the year they are poised to do well again.”