NEW YORK - Shoppers are showing signs of pulling back on spending for discretionary items such as clothing and home goods as gasoline and groceries eat up more of their paychecks.

Those pressures led many retailers Thursday to report only modest revenue increases in May, the latest sign of the economy hitting a soft patch.

Retailers that cater to wealthy shoppers and warehouse clubs that also sell gas, such as Costco, reported the biggest gains.

For most of the spring, consumers seemed to shrug off rising prices. Now, gasoline costing $1 per gallon more than a year ago and higher grocery bills are "finally taking a bite and affecting sales," said Ken Perkins, president of research firm Retail Metrics. "It definitely raises the caution flag going into the summer."

Revenue rose 5.4 percent overall at stores open at least a year among 27 retailers surveyed by the International Council of Shopping Centers. Excluding gasoline, the figure rose 3.7 percent.

"On the surface, the numbers look pretty good," said Mike Niemira, the group's chief economist. "But it is being driven by a very narrow set of retailers."

Revenue from stores open at least one year is a key indicator of a retailer's health because it excludes stores opened or closed during the year.

Among the reports Thursday by individual retailers, chains based in the Philadelphia area posted mixed results for May:

Rite Aid. The Camp Hill drugstore operator said revenue at stores open at least a year had risen 1.3 percent from May last year. Pharmacy revenue grew 1 percent and prescriptions 0.1 percent. Revenue from the front end of the store, where such items as cosmetics, magazines, and candy are sold, increased 1.8 percent.

Destination Maternity. Same-store sales for the month were down 8.6 percent, the Philadelphia maternity retailer said. The company, which reports on a calendar-month basis, said having one fewer Saturday than last year's period was a factor, along with severe May weather in parts of the country and continued economic doldrums.

Bon-Ton Stores. Same-store sales fell 2.3 percent last month, which the department-store chain attributed to slow traffic for warm-weather merchandise such as intimate apparel, men's sportswear, and children's clothing. Bon-Ton has headquarters in York and Milwaukee.

Among national retailers, Target's revenue at stores open at least a year rose 2.8 percent, below the 3.5 percent analysts expected, according to FactSet.

"Our guests continue to shop cautiously in light of higher energy costs and inflationary pressures on their household budgets," Target Corp. chief executive Gregg Steinhafel said.

Stores that cater to middle- and lower-income shoppers fared worse than more expensive stores. Luxury retailer Saks Inc. reported that May results had jumped 20.2 percent, and Nordstrom Inc. also beat expectations. Sales at Macy's rose 7.4 percent.

But midpriced department stores, such as Dillard's, J.C. Penney, and Kohl's, all missed expectations for May sales.

Inquirer staff writer Roslyn Rudolph contributed to this article.