Wal-Mart executives declined to discuss their plans to expand food and grocery sales.

But Robert F. Buchanan, a retail analyst with Alex. Brown & Sons in Baltimore, said there was little doubt that Wal-Mart was "moving big into food." Food retailing accounted for $362 billion in sales last year, according to Alex. Brown, compared with $84.6 billion in discount department store sales last year. Mr. Buchanan said that building up grocery sales will play an increasingly large role in the company's stated goal of reaching $100 billion in sales by the end of the decade.

Last summer, Wal-Mart struck a deal with Mexico's biggest retailer, Cifra S.A., to open warehouse-style stores in Mexico that would sell a range of products, including stationery, electronics and food. Uneasy Ripples

Some in the food industry are concerned that Wal-Mart will gain too much power as it expands into an important new area of food retailing. In Canada and Europe, where there is a far greater degree of consolidation in food retailing, a few large retailers wield tremendous influence over the food industry. "It makes negotiating more difficult," said Mr. McCarthy of Campbell.

Already, some of Wal-Mart's recent moves are sending uneasy ripples through the food industry. In November, Wal-Mart told manufacturers that it would no longer deal with the brokers who act as middlemen between manufacturers and retailers.

Wal-Mart says cutting out the brokers will improve communications and allow the company to react quicker in ordering. The company argues that the sheer volume of its business -- it had sales of $32.6 billion last year -- mandates that it has direct ties to its suppliers. 'This Is Not Passive'

Some food retailing executives have a different interpretation. "It's Wal-Mart flexing its muscles and saying we are a national, dominant retailer and we decide the rules of a game, and not you," said Brian Sharoff, president of the Private Label Manufacturers Association in New York. "At one time retailers were viewed as passive. This is not passive."

Grocers are also worried that Wal-Mart's decision to stop working with brokers will give it a price advantage. Food processors pay brokers small commissions for selling their products. Grocers say that manufacturers dealing directly with Wal-Mart could pass the savings on to the chain in the form of discounts.