Consumers persevered at stores and malls in August, shopping despite soaring gas prices and giving many of the nation's biggest retailers surprisingly solid sales. But the outlook for consumer spending in the months was uncertain, with Hurricane Katrina and higher energy prices expected to take a toll on the overall economy.

As merchants reported sales figures Thursday, a diverse group of retailers enjoyed strong results, including warehouse clubs like Costco Wholesale Corp. (COST), teen retailers such as Wet Seal Inc. (WTSLA), moderate-priced department stores such as J.C. Penney Co. Inc. (JCP) and Kohl's Corp. (KSS) and upscale merchants like Nordstrom Inc. Wal-Mart Stores Inc.'s sales came in slightly below analysts' estimates as low-income shoppers feel the sting of higher energy costs.

There were some exceptions, notably Limited Brands Inc. (LTD) and Gap Inc. (GPS), both of which reported sales drops as they continue to stumble with the wrong fashions.

Some analysts were encouraged by the overall figures.

"I am a little surprised about the strength," said Ken Perkins, president of RetailMetrics LLC, a research firm in Swampscott, Mass. "This was a difficult month given the hot weather and the psychological and financial impact of rising energy prices."

He noted that 68 percent of the retailers that reported August results beat Wall Street expectations.

But Michael Niemira, chief economist at the International Council of Shopping Centers (search), was more cautious, noting that the August gains were on top of tepid results a year ago, when consumers cut back their spending amid growing worries about the economy.

"Yes, the numbers look good, but they should have looked better," said Niemira. "Beneath the surface, it shows some strain."

The International Council of Shopping Centers-UBS sales tally of retailers rose 3.6 percent in August, below the 4.0 percent forecast. That was on top of a slim 1.3 percent increase in August. The sales tally is based on sales at stores opened at least a year, known as same-store sales, which is an important measure of a retailer's health.

August's spending pace was about in line with the 3.75 percent average in the first six months of the retailers' fiscal year.

But analysts fear shoppers will pull back in the weeks ahead as gas prices at the pump soar past $3 in many parts of the country, a result of the devastating fallout of Katrina, which restricted already limited refinery output. And the full impact of higher energy costs won't be felt until later this fall, when consumers get their home heating bills.

"We are going to see the effect of higher energy prices trickle up to the middle-income consumers," Perkins said.

The impact of Katrina is still unclear, but worries are mounting that the fallout will slow what has been a steadily growing economy and reverse the solid pace in job gains. The latest report from the Labor Department on job claims, announced Thursday, was not encouraging.

The government said the number of Americans filing new claims for unemployment benefits rose by 3,000 last week to a seven-week high of 320,000. Those claims numbers are expected to dramatically rise in the weeks ahead as laid-off workers in New Orleans and other areas affected by Katrina file claims.

Wal-Mart (WMT) reported same-store sales were up 3.3 percent, slightly below the 3.4 consensus from analysts polled by Thomson Financial. Total sales rose 10.2 percent.

Meanwhile, rival Target Corp. (TGT), whose trendy merchandise appeals to a more upscale customer, continued its winning streak. It posted a 6.3 percent gain in same-store sales, beating the 5.4 percent estimate from analysts. Total sales rose 12.2 percent.

Costco announced a 9 percent gain in same-store sales, beating the 7.9 percent estimate from analysts. Total sales rose 12 percent.

BJ's Wholesale Club Inc.'s (BJ) same-store sales rose 5.6 percent, besting the 4.7 percent estimate from Wall Street. Total sales rose 12 percent.

Upscale stores Nordstrom (JWN) and Neiman Marcus Group Inc. continued to generate robust sales. Nordstrom scored an 8 percent increase in same-store sales, above the 4.3 percent estimate. Total sales rose 9.5 percent.

Neiman Marcus had a 8.2 percent gain in same-store sales, surpassing the 5.7 percent estimate. Total sales rose 6.5 percent.

Penney had a 2.8 percent increase in same-store sales, slightly better than the 2.7 percent estimate. Total sales rose 3.2 percent. The company said that the best performing categories were women's accessories, fine jewelry, home furnishings and shoes. Back-to-school merchandise also did well.

Meanwhile, Kohl's enjoyed a 4.6 percent gain in same-store sales, better than the 3.7 forecast. Total sales rose 14.3 percent.

But Federated Department Stores Inc. had a 1.1 percent gain, below the 2.0 percent estimate. Total sales rose 1.3 percent.

Talbots Inc. had a 2.3 percent increase in same-stores sales, below the 3.4 percent estimate. Total sales rose 9 percent.

Limited suffered a 3 percent drop in same-store sales, worse than the 1.1 percent forecast. Total sales were virtually unchanged from a year ago.

Gap had a 9 percent drop in same-store sales, worse than the 4.6 percent decline that analysts had expected. Total sales declined 5 percent.

The teen sector fared well this back-to-school season.

Wet Seal enjoyed a 48.3 percent increase in same-store sales, beating lofty expectations for a 33.1 percent gain. Total sales rose 14.8 percent.

Bebe Stores Inc. announced a robust same-store sales gain of 16.9 percent, though it was below the 21.4 percent estimate. Total sales rose 26.5 percent.

On Wednesday, American Eagle Outfitters Inc. (AEOS) reported an 11.8 percent gain, about in line with the 11.9 percent estimate from analysts. Total sales rose 18.7 percent gain.

On Monday, teen retailer Abercrombie & Fitch Co. (ANF) , reported a 24 percent gain in same-store sales increase, surpassing the 18.6 percent estimate. Total sales rose 36 percent.