Costco Wholesale Corp. (COST), the largest U.S. warehouse club operator, on Thursday reported a 12 percent increase in quarterly profit, helped by demand for gasoline and food.

The retailer, which competes with Wal-Mart Stores Inc.'s (WMT) Sam's Club, said net income rose to $215.8 million, or 45 cents per share, in the fiscal first quarter ended on November 20, from $193.2 million, or 40 cents per share, a year earlier.

The company said its first-quarter results included about 1 cent per share in pretax charges related to damage from Hurricane Wilma in Florida.

Analysts, on average, had expected earnings of 45 cents per share, according to Reuters Estimates.

Costco said net sales in the quarter rose about 12 percent to $12.66 billion from $11.34 billion in the year-earlier period. Including membership fees, total revenues were $12.93 billion, up from $11.58 billion a year earlier.

Costco has weathered aggressive competition from Sam's Club by selling luxury goods such as diamond rings and even Picasso sketches in addition to the usual warehouse club array of bulk toilet paper and supersized ketchup bottles.

Sam's Club has answered with its own upscale merchandise including a $560,000 diamond necklace.

Costco's shares trade at almost 22 times analysts' profit forecasts for next year, compared with 18 times for Wal-Mart, according to Reuters Estimates.

Last week, Costco reported disappointing November sales, largely because a strengthening U.S. dollar deflated international results. Sales were better than expected in September and October, however, helped by sales of gasoline and food.

Costco has gas stations at many of its warehouse clubs, so its sales have benefited from steep oil prices. The retailer tries to keep its pump prices below those of traditional gas stations in the hope of luring shoppers into its stores.

But in prior quarters soaring energy costs hurt profit, so analysts were hopeful that receding prices would boost Costco's earnings this quarter.

The retailer gave no details about its gasoline business in a brief press release, but is expected to provide more information on that and its profit forecast during a conference call later on Thursday.

Costco also said it plans to open 18 to 20 new stores in its current fiscal year, which ends September 3.

Costco's stock closed at $49.35 on the Nasdaq on Wednesday, just off a 52-week high of $51.21 notched on November 30.