NEW YORK — Costco’s stock slipped Thursday, a day after the warehouse club operator said its fiscal second-quarter profit fell nearly 9 percent as costs rose.

Sales, however, did rise, the company said late Wednesday. Sales at its stores open at least a year, considered an important measure of a retailer’s health, rose 1 percent. The gain came from its roughly 490 U.S. stores, with sales rising 3 percent. They fell 7 percent in Canada and fell 3 percent at its other international stores.

The Issaquah, Washington, company has nearly 700 total stores around the world.

Rising costs took a bite out of its profit. Merchandise costs rose 2.4 percent to $24.5 billion and its other costs rose 6 percent to $2.8 billion.

Costco reported net income of $546 million, or $1.24 per share, in the quarter ended Feb. 14, compared with $598 million, or $1.35 per share, in the same quarter the year before. Analysts expected earnings of $1.28 per share, according to FactSet.

Revenue, which includes sales and membership fees, rose 2.6 percent to $28.2 billion in the quarter, below the $28.5 billion analysts expected, according to FactSet.

Shares of Costco Wholesale Corp. fell $2.47 to $150.32 in afternoon trading Thursday