SOME customers said they were originally from Cuba, others from Italy, Spain and Puerto Rico, and some said they have been driving from as far away as Trumbull and Bridgeport to do their regular shopping at Bongiorno Supermarket in Stamford for years.  One after another on Tuesday, shoppers drove through what was, until last weekend, the parking lot of Bongiorno's, leaving in disbelief when told the store was closed and would be reopened soon as a Stop & Shop supermarket.  ''Where will I get my Terra Nova bread now?'' asked Maria Joyce of Trumbull, who said she had been shopping there since her family immigrated from Italy. ''I guess I'll have to go to Arthur Avenue,'' she said, referring to the street in the Bronx.  After more than 50 years in the city, and with hardly any notice, the family-owned and operated Bongiorno's was bought by Stop & Shop of Quincy, Mass., for an undisclosed amount late last month, and then shut down at the close of business on July 31. After a frenzied four days of renovations, the store reopened as a Stop & Shop on Thursday morning.  Faith Weiner, a spokeswoman for Stop & Shop, said the company is also seeking approval to build a new store at West Main Street and Alvord Lane in Stamford, across from a Shop Rite store now under construction. She said the current location would remain open until a new Stop & Shop store is completed. She also said that the store's 160 employees were invited to work at Stop & Shop.  When asked if Stop & Shop was trying to gain a foothold in the neighborhood before Shop Rite, Ms. Weiner said:  ''An opportunity to serve the market was presented to us and we decided to pursue it. Our focus is on how to bring our version of one-stop shopping to customers served by our market.''  Maurice Nizzardo, the director of operations for Bongiorno Industries and the son-in-law of George Bongiorno, the store's founders, said the company is leasing the land on which the store sits to Stop & Shop. He said Bongiorno Industries owns 1 million square feet in the city and will continue to own and operate a liquor store, gas station and car wash near the store.  Mr. Nizzardo said Bongiorno Supermarket was special because of the Eastern European, Hispanic, Italian, Asian and other ethnic foods it carried. He said the store paid particular attention to its fish, meats and produce.  ''We would send our own trucks to the Fulton Fish Market and Hunts Point produce and meat terminals in New York on a daily basis Mondays through Fridays,'' he said.  Berbely Zayas, 15, of Stamford, said her family had been going to the store for its meats since they came from Puerto Rico eight years ago.  ''They had the best prices, too,'' she said. ''We really don't know where we're going to shop now.''  Mr. Nizzardo said he hoped that Stop & Shop would retain some of Bongiorno's inventory. Ms. Weiner said Stop & Shop stores carries some items specific to its market. A quick look inside the store on Thursday morning after it had opened did indeed find Terra Nova bread, but the meat selection had changed and the special on jumbo eggs that Bongiorno's continually ran was gone.  Mr. Nizzardo said Bongiorno Supermarket was doing about $500,000 in sales each week.  In the last 10 years, there were many people who were interested in the business,'' he said. ''Stop & Shop was the only company, pretty much, that was willing to take on the employees, which was a major concern for us. We wanted to give our employees stability and benefit packages, so that they wouldn't be left in the lurch.''  In a statement, George Bongiorno said the sale would benefit everyone.  ''We thought this might be an opportunity to enable our employees and our customers to be well-served today and in the future and also allow the family to pursue other interests,'' he said.  Dannel Malloy, the mayor of Stamford, said it meant the city was losing a ''great store.''  ''It's been very community-minded,'' he said. ''It's a great family and we look forward to having them in the community, just not in the supermarket business.''  But for many, like Clyde Nicholson of Bridgeport, who said he regularly pulled off Interstate 95 to get lunch at Bongiorno's, finding the store closed was disheartening.  ''I passed by many other stores to come here,'' he said. ''This was my store. This is one of the saddest days of my life.''  To others, it was a sign of the times.  ''It's kind of sad because its was a real community establishment,'' said Klaus Schmidt, a Stamford restaurant owner who said he knows the Bongiorno family and was a regular customer. ''But I guess the big boys are taking over.''  Mr. Nizzardo said the family did have an emotional attachment to the store and its customers, but he said closing quickly was best.  ''We feel we made a good decision,'' he said. ''Once the final agreement was made, we didn't see any advantage in letting the store linger.''
Bongiorno Supermarket in Stamford, Conn, closes; customers fear they will not be able to find favorite items when store reopens as Stop and Shop; photo (M)