U.S. retail sales numbers for September will likely foreshadow the ghost of Christmas past, as consumers continue curtailing their spending amid the highest unemployment rate in over a quarter century.

September same-store sales data, to be released Thursday, are expected to show a continued decline, demonstrating that retailers still aren't able to build momentum despite easy comparisons from a year ago.

"This will be the season of the blue jean instead of the Blu-Ray," said Ellen Davis, vice president at the National Retail Federation.

The best thing that might be said is that profit margins may not take the big hits they did last year because retailers have been ordering less merchandise. As a result, while still expected to be highly promotional, retailers' discounting is seen as being more planned this year than a lot of the across-the-board slashing that occurred in 2008.

Still, consumers' frugality means it will take a lot of $10 and $20 toys and basic apparel purchases to counter an expected slack in sales of high-end electronics and other upper-end merchandise.

The National Retail Federation on Tuesday projected U.S. holiday sales over November and December will fall 1% this year to $437.6 billion. Last year, sales fell 3.4% over the same period, to $441.97 billion, marking the worst holiday season for retailers in the four decades that the data's been tracked. The 10-year average rate is growth of 3.4%.

Roughly 70% of consumers plan to spend less or the same on gifts this year than they did during the 2008 holidays, said consumer data tracker BIGresearch in data released Tuesday.

In general, September "definitely foreshadows what's going to happen during the holidays," said Pam Goodfellow, senior analyst at BIGresearch.

September same-store sales are expected to show a 1.1% drop, according to the 30 retailers tracked by Thomson Reuters. The figure does not include Wal-Mart Stores Inc. (WMT), which stopped reporting same-store-sales earlier this year.

September is something of a testing ground, marking the first month that retailers are up against a same-store sales drop from a year ago. But the decline is expected to be even bigger than September 2008's 0.9% comparable-store sales decline.

Off-price retailers and discounters are expected to have had the best September, prompting some analysts to see upside to estimates for TJX Cos. (TJX), Ross Stores Inc. (ROST) and even Target Corp. (TGT).

Department stores continue to be the recession's big strugglers, with same-store sales declines expected for all but one of the seven chain stores that Thomson Reuters tracks. Kohl's Corp. (KSS) is projected to see a 0.1% gain, while Saks Inc. (SKS) is at the other end of the spectrum, with an 11.1% drop projected.

Apparel retailers are seen as a mixed group, with positive comparisons expected from Aeropostale Inc. (ARO) and Buckle Inc. (BKE), and possibly even Gap Inc. (GPS). But Abercrombie & Fitch Co. (ANF) remains a market-share loser, with same-store sales expected to drop 20.8%, the biggest decline of any retailer Thomson Reuters tracks.

-By Karen Talley, Dow Jones Newswires; 212-416-2196; karen.talley@dowjones.com