February sales numbers that top U.S. chains report this week will be the first sign of shoppers' ability and willingness to pay more for clothing and household items now that gas prices are rising.

More than two dozen U.S. store chains, from high-end department stores Nordstrom Inc and Saks Inc to discounters Target Corp and Costco Wholesale Corp will report February sales on Wednesday and Thursday.

Wall Street analysts expect same-store sales -- sales at outlets open at least year -- rose 3.6 percent last month, according to Thomson Reuters' Same-Store Sales Index estimates updated Tuesday afternoon.

The International Council of Shopping Centers expects February chain store sales to be up 2.5 percent to 3 percent.

Stores should get a boost from the severe winter storms that plagued much of the country in late January and forced shoppers to postpone purchases into February.

But gasoline prices have begun climbing, after tumult in Libya sent oil prices to 2-1/2 year highs last week, and could severely dent sales this spring.

How much gas prices go up will determine whether retailers' shares, which have stalled since December, resume their climb.

We believe sales have improved more than the stocks reflect, Credit Suisse analyst Gary Balter wrote in a research note on Monday. Assuming oil finds its way back down, (this) positions this group for a mini-rally.

The Standard & Poor's Retail Index <.RLX> is up 0.2 percent this year, while the broader S&P 500 <.SPX> is up 5.2 percent.

(For a graphic comparing U.S. same-store sales and the S&P Retail Index, please see http://link.reuters.com/quk38r.)


The top February same-store sales gains should come from warehouse club operator Costco and Saks, with estimated increases of 7.0 percent and 5.1 percent, respectively.

The weakest performers are expected to be Gap Inc and teen retailer Hot Topic , with estimated declines of 0.8 percent and 5.2 percent, respectively.

In a sign that shoppers are steadily growing more able to spend on non-essentials, jewelry sales rose over Valentine's Day at several mid-tier retailers.

Zale Corp said last week its same-store sales rose 12 percent over Valentine's Day weekend compared to last year, and Kohl's Chief Executive Kevin Mansell last week told Reuters that jewelry was outperforming other merchandise in February.

Among retail chains reporting this week, Costco, Target and J.C. Penney Co Inc are also large sellers of jewelry.

Nomura Securities analyst Paul Lejuez expects Valentine's Day to be a boon for Limited Brands , parent of lingerie chain Victoria's Secret. Wall Street is expecting Limited's same-store sales at to be up 8.3 percent.

Last year, as consumer spending continued to recover, gas prices stayed well below 2008 highs. But now, shoppers have to pay more at the pump, which is likely to reduce their store visits and impulse buys.

There is this tremendous inflationary issue looming -- that's going to hold business back, no question about it, said Mark Cohen, a professor at Columbia University's business school and a former CEO of Sears Canada . He called the consumer spending recovery meager.

(Reporting by Phil Wahba; Editing by Richard Chang and John Wallace)