Costco Wholesale Corp reported a 6 percent rise in July sales at stores open at least a year, helped by inflation in gasoline prices and strengthening foreign currencies, marginally beating market expectations.

The company said it saw the strongest results in the midwest, Texas, southeast and northwest regions in the United States. Overseas, Korea and Taiwan performed the best.

Analysts were expecting the largest U.S. warehouse club operator's same-store sales to rise 5.5 percent, according to Thomson Reuters data. Costco same-stores sales had missed market expectations for the last three months.

For the four weeks ended August 1, net sales rose 8 percent to $5.86 billion from the previous year. July had 28 days of sales, same as last year and was not impacted from any calendar shift or holidays, the company said.

Shares of Costco closed at $57.40 Wednesday on Nasdaq.

(Reporting by Jennifer Robin Raj in Bangalore; editing by Simon Jessop)