By Maria Armental

Costco Wholesale Corp. reported better than expected sales results for December as online shopping soared.

The warehouse chain reported net sales of $19.14 billion for the five-week period ending Jan. 3, up 12.3% from a year earlier.

Comparable sales, a closely watched performance metric that looks at sales at warehouse-club locations open for more than a year, rose 10.7%. Excluding the impact from gasoline sales and currency swings, core comparable sales rose 10.9%.

Analysts surveyed by Consensus Metrix expected a 10.1% comparable-sales increase, or 11.2% when adjusted for gas sales and currency swings.

The increase was driven by frozen foods, sundries and liquor sales, despite lower frequency of sales world-wide because of restrictions tied to the coronavirus pandemic, the company said.

David Sherwood, assistant vice president for financial planning and investor relations, said in a prerecorded call that traffic declined in Canada, Mexico and the U.K. but rose in the U.S., Costco's largest single market by number of warehouse locations. The lower shopping frequency, however, was more than offset by higher spending, with the average transaction world-wide rising 11.4% from the year-ago period, he said.

Costco, one of the companies that remained open during the coronavirus pandemic because its services were deemed essential, has largely fared well financially during the pandemic, offering one-stop shopping for such things as food and appliances. Costco operates 803 warehouses, including 558 in the United States and Puerto Rico.

The company said that e-commerce comparable sales rose 62.5% in December.

As Covid-19 cases increased around the country, shoppers generally turned to online shopping. Shopper visits to physical stores declined 33% for the six-week holiday period, according to Sensormatic Solutions, which tracks footsteps with cameras in stores. Sensormatic had projected that foot traffic would fall 22% to 25% in the period.

Shares of Costco, up nearly 27% in the last 12 months, closed down 1.5% on Wednesday at $370.02.

Write to Maria Armental at maria.armental@wsj.com

(END) Dow Jones Newswires

01-06-21 1741ET