NEW YORK — American consumers went into hiding in September, leaving retailers with dismal sales and an uncertain future well beyond the holiday season as the fallout from the financial meltdown pushes spending even lower.

As retailers reported their monthly sales figures Wednesday, even discounters weren't immune to shoppers' mounting worries.

"Discretionary spending has come to a trickle," said Ken Perkins, president of research company RetailMetrics. "Consumers are the most worried I have seen since at least the 1991 recession. "

Wal-Mart Stores, the world's largest retailer, said sales of discretionary items were weak as it posted solid results that were nevertheless a bit below expectations. Target Corp. fared far worse, reporting a bigger-than-expected drop and is cutting its profit outlook.

Luxury stores such as Neiman Marcus Group and Saks suffered sharp drops. Many mall-based apparel stores and department stores including J.C. Penney Co. and American Eagle Outfitters find themselves mired in a slump.

Before the financial meltdown began in the middle of last month, customers had already been switching to lower-price brands and stores, cutting back on essentials and making other changes like mending their clothes instead of buying new ones.

"Weakness in consumer spending is a significant drag on overall economic activity," said Scott Hoyt, senior director of consumer economics at economy.com, who now predicts declines in consumer spending, adjusted for inflation, through the first quarter of 2009.