The Great Atlantic & Pacific Tea Co. opened three of its new limited-selection discount food stores in the Washington suburbs yesterday -- the first of at least seven such stores to be opened here this fall.

A&P'S venture, designed to help rebuild volume in a lucrative market where it has lagged came as another retailer, behind Giant Food Inc. and Safeway Stores, came as another retailer, Food Fair, put its area Pantry Pride stores up for sale.

The innovative A&P stores are called Plus, the same name used in Germany for similar units owned by the Tengelmann Group, a European retailer that purchased controlling interest in A&P last spring.

Instead of the several thousand different items stocked in conventional supermarkets, the Plus stores carry only about 850 products, 550 of them private-label Plus brands.

Fritz Teelen, the German supermarket executive who is president of A&P'S Plus Discount Foods subsidiary, said the new operation was started because "we think the inflation rate in the United States is so big that we can get a lot of customers who are price-conscious and want to save money."

Loeb Corp., a food wholesaler based in Ottawa, operates four Bag 'N' Box limited-selection stores here and has helped to set up two independents which it also supplies, according to Donald Maxson, Loeb's Washington division sales manager.

The first of the four stores opened in Silver Spring Jan. 3, followed by units in Baltimore and Glen Burnie. The fourth Bag 'N' Box, in Upper Marlboro, had its grand opening yesterday.

Bag 'N Box plans to open 8 to 10 more stores in the Washington area during the next year and to help set up and supply 10 more independent units.

The Bag 'N Box stores average 8,000 square feet of space and offer between 500 and 550 items, Maxson said.

Teelen said A&P plans to have 50 Plus stores in operation by January, when the chain's fiscal year ends. Eventually 150 Plus stores will be open.

In another development in the Washington food business, Food Fair Stores Inc. reportedly is looking for a buyer for its six Pantry Pride stores in the area. Food Fair, now seeking to reorganize under federal bankruptcy law, is expected to file its plan for debt payment and corporate survival next week.

Safeway Stores officials denied trade reports that the nation's top food retailer is interested in buying the Pantry Pride units here.

A&P'S new no-frills stores don't cash checks or take manufacturers' coupons -- although they do accept food stamps. Merchandise is stacked in cartons and customers must bag and box their own orders.

The first three Plus stores in the region are in former A&P stores that were closed a few months ago because the company said they were unprofitable: 1440 Jefferson Davis Highway, Woodbridge; 610 Ritchie Highway, Severna Park; and New Silver Hill Road, Suitland; Four more units will be opened in October and November, Teelen said yesterday. The second batch of stores will be located on South Wakefield Street in Arlington, on Lee Highway in Fairfax, in Bladensburg and Randallstown.

The American Plus stores average about 10,000 square feet -- several times larger than their German counterparts -- but carry less merchandise, Teelen said.

A&P claimed the stores' prices are as much as 30 percent cheaper than comparable national brands.