The nation's retailers yesterday reported another month of poor sales, prompting analysts to revise downward their projections for the crucial Christmas season.

Three of the top four retailers said their October sales were down from the year before while No. 1 Sears, Roebuck and Co. managed to post a small increase.

The poor performance for the month not only cast doubts on how good Christmas business will be this year, but also threw cold water on prospects that increased consumer spending will lead the nation out of the recession.

The results are even poorer than they appear because they are compared with the particularly weak sales of October 1981, said Monroe H. Greenstein, an analyst at the securities firm Bear, Stearns & Co.

"The consumer would still rather work down debts and save as opposed to spend," said "The consumer has the ability to spend, the consumer just chooses not to."

Many economists have said the economy's recovery hinges on higher consumer spending that would trigger new wholesale orders, boost manufacturers' production and lead to the rehiring of laid off workers.

Jeffrey Feiner, an analyst with Merrill Lynch, Pierce, Fenner and Smith Inc., also expressed disappointment in the October figures, although he noted they did show a slight improvement from the August-September pace.

"The high unemployment rate and the likelihood unemployment levels will go higher have pressured consumer spending trends," he said.

Both Feiner and Greenstein said they now expect a smaller increase in sales than they had previously forecast for the next two months, when retailers ring up their biggest sales and much of their profits for the year.

While several months ago analysts were predicting a rise of 7 percent to 8 percent over year-earlier sales, Greenstein now foresees a gain of 4 percent to 6 percent. Feiner said he had reduced his forecast to the same range, now projecting a "gradual improvement, not ebullient."

"Nevertheless, aided by lower year-to-year inflation and interest rates, we expect to see some pickup in the all-important Christmas selling season," Feiner added.

Sears, Roebuck and Co. Chairman Edward Brennan said sales of appliances, television sets and the like picked up during October, the first indication that consumers are willing to spend for big-ticket items.

Sears said its October sales inched up 3.8 percent to $1.593 billion from $1.535 billion in the same month last year. For the first 39 weeks of 1982, sales were up 2 percent to $14.32 billion from $14.05 billion last year.

K mart Corp., the No. 2 retailer, said its sales dipped 2.1 percent to $1.183 billion from $1.208 billion a year ago. K mart, based in Troy, Mich., said its 39-week sales were $11.63 billion, up 2.3 percent from the year-ago $11.37 billion.

J. C. Penney Co., the New York-based retailer that ranks No. 3, said its sales dropped 2.4 percent to $809 million from $829 million. Penney said that so far this year it sales totaled $7.19 billion, down 0.3 percent from $7.17 billion.

F. W. Woolworth Co., No. 4, said its sales were down 2 percent to $521 million from $532 million. Woolworth, also headquartered in New York, said the sales for the first 39 weeks were $5.1 billion, up 1.4 percent from $5 billion.