Net income in the quarter ended May 6 rose to $386 million, or 88 cents a share, from $324 million, or 73 cents, a year earlier, the Issaquah, Washington-based company said Thursday in a statement. Excluding some items, profit was 89 cents a share. Analysts projected 87 cents, the average of 24 estimates.

Chief Executive Officer Craig Jelinek has been luring customers with low prices on everything from baked goods to gasoline. The chain has also added more service areas, such as pharmacies and vision centers, to its locations to claim more of its members’ spending.

“We are particularly encouraged by the gross margin expansion,” Sean Naughton, an analyst for Piper Jaffray & Co. in Minneapolis, wrote in a note to clients. There are more opportunities for margins to increase, he said.

Costco rose 1.2 percent to $84.27 at 9:56 a.m. in New York. The shares were little changed this year through Wednesday.

The retailer’s in-store gross margin, or the percentage of store sales left after subtracting the cost of goods sold, widened to 10.55 percent from 10.51 percent a year earlier. That marked the first year-over-year gain in five quarters.

Same-store sales, a key metric for retailers because only established locations are counted, rose 5 percent, excluding changes in gas prices and currency rates. Net sales gained 8.2 percent to $21.8 billion, and revenue from membership fees advanced 9.2 percent to $475 million.

The increase in same-store sales was slower than the 7 percent gain in Costco’s previous two quarters. That decelerating growth and reduced traffic at its gas pumps raises concerns that sales won’t rebound this year, Daniel Binder, an analyst for Jefferies & Co. in New York, wrote in a note to clients.