* August net sales up 9 percent at $5.9 billion
* Says gasoline prices, foreign currency gains helped
Sept 2 (Reuters) - Costco Wholesale Corp (COST.O), the largest U.S. warehouse club operator, reported a 7 percent rise in August sales at stores open at least a year, aided by a surge in gasoline prices and foreign currency gains.
Midwest, Texas, northwest and Los Angeles performed best for the company within the United States.
Internationally, Korea, Canada and Japan were the outperformers, Costco said on Thursday.
Analysts were expecting same-store sales to rise 4.2 percent, according to Thomson Reuters data.
For the four weeks ended Aug 29, net sales at the Issaquah, Washington-based company rose 9 percent to $5.9 billion.
Discounts and back-to-school selling had helped teen retailers Hot Topic Inc HOTT.O and Zumiez Inc (ZUMZ.O) beat August same-store sales estimates. [ID:nSGE6800LA] (Reporting by Krishna N. Das in Bangalore; Editing by Dan Lalor)