(Reuters) - Costco Wholesale Corp (COST.O) on Thursday 7 January reported a better-than-expected nine percent rise in December sales at stores open at least a year, helped by an increase in gasoline prices and stronger foreign currencies.

Analysts, on average, were expecting the company's same-store sales to rise 7.9 percent, according to Thomson Reuters data.

Same-store sales at its U.S. locations increased 5 percent, while international sales rose 25 percent.

Excluding inflation in gasoline prices, U.S. comparable sales would have been up 2 percent, while on a local currency basis, the company said international same-store sales increased 10 percent.

Costco said total sales in the 5 weeks ended January 3 increased 11 percent to $8.26 billion.

Customers pay an annual fee to shop at Costco's warehouse locations, which sell everything from digital cameras and watches to bulk-sized packages of toilet paper and soda.

The largest U.S. warehouse club operator also sells gasoline, drawing in shoppers looking to fill their tanks with cheap fuel.

(Reporting by Santosh Nadgir in Bangalore; Editing by Kavita Chandran)