The nation's major chain-store retailers yesterday reported poor September sales, confirming ideas that consumers are feeling the double pinch of higher oil costs and a rising unemployment rate, analysts said.

Analysts said worries about recession and a possible war in the Persian Gulf kept consumers on the sidelines. And they said the retailers' reports -- some of which showed a decline from September 1989 levels -- did not augur well for a robust Christmas shopping season.

"It could get worse ... ," warned Jeffrey Feiner of Merrill Lynch & Co. "We believe that for the first time in a long time, we will have two very poor Christmases back to back."

September's results came as no surprise. August sales, which normally are boosted by back-to-school shopping, showed signs of a spending slowdown. The September weather also affected sales, as temperatures ran above the norm, and few consumers were in the mood to shop for winter clothing.

The nation's largest retailer, Sears, Roebuck & Co., said sales at stores open at least a year rose 4.4 percent for the five weeks ended Oct. 6, while sales from all of its stores rose 4.2 percent. K mart Corp. said its same-store sales inched up 0.7 percent although overall sales rose 10.2 percent.

Wal-Mart Stores Inc., the discount retailer that consistently outperforms the rest of the industry, reported a same-store sales gain of 9 percent and a 24 percent rise overall.

May Department Stores Co., which owns the Hecht Co., said its same-store sales fell 1.8 percent, while overall sales picked up 3.5 percent. J.C. Penney Co. said its same-store sales fell 3.4 percent and overall sales were off 2.3 percent; Dayton Hudson Corp. reported a 2 percent decline in same-store sales and overall sales up 11.3 percent; and the Limited Inc., the nation's largest specialty apparel retailer, said its same-store sales dropped 3 percent while overall sales rose 10 percent.

Woolworth Corp. reported a 2.1 percent gain in same-store sales, and a 6.2 percent rise overall.

Merrill Lynch's Feiner predicted earnings would decline again in the fourth quarter. A slump in profits then could be devastating for retailers, who depend on this period for about 50 percent of their full-year earnings.