The nation's largest retailers yesterday reported lackluster sales in January, but store owners and Wall Street analysts shrugged off the results.

"January just doesn't mean anything," said Fred Wintzer, a retail industry analyst at the Alex. Brown & Sons Inc. investment firm in Baltimore.

"I don't think we can generalize anything from glancing at the numbers," said Jeffrey B. Edelman, an analyst with Drexel Burnham Lambert Inc.

Consumer spending is crucial for the nation's economic health because it accounts for about two-thirds of the gross national product, which is the total retail value of all goods and services produced. Weakness in spending raises concern about the likelihood of a recession because a decline carries with it the possibility of a manufacturing slowdown.

January is usually a slow time for stores because consumers are paying off the holiday debts they ran up in December.

Stores also have extensive price markdowns in January to clear out holiday and winter merchandise. Retailers who had better sales last month tended to have larger inventories left over from December. "Generally, a good January reflects a bad Christmas," said Wintzer.

Sears, Roebuck and Co., the nation's largest retailer, said its sales rose 5.3 percent in January and 3.5 percent for the fiscal year, compared with 1986.

K mart Corp. reported that its sales rose 6 percent in January and 7.6 percent for the year.

Wal-Mart Stores Inc. said its total sales increased 29 percent in January and 34 percent for the year.

While January is not considered a trend-setting month, analysts repeated predictions that sales would continue at a sluggish pace in the early part of this year, with an increase expected in the second half.