NEW YORK – On paper, it seems like the perfect fit: the city that never sleeps and the top purveyor of 24-hour-a-day convenience.

In fact, when a 7-Eleven opened in Manhattan this summer for the first time in 23 years, New Yorkers happily queued up in long lines to purchase ice-cold Slurpees from the new store on a bustling corner of East 23rd Street.

But not all residents have welcomed the presence of the world’s largest convenience store chain with such delight. The third 7-Eleven in Manhattan is set to open in mid-November in an affluent, leafy neighborhood on the city’s Upper East Side, and its denizens are none too pleased.

“This monstrosity, this carbuncle” is how one angry resident described the arrival in a flier posted last week on Curbed.com, a local real estate blog.

“This will destroy two of the most beautiful, tranquil blocks in the neighborhood, add to the already horrendous garbage, vermin and rodent problem with rowdiness, bringing beer drinkers, taxi’s on breaks and other undesirables,” fumed the writer, who urged neighbors to complain to their elected officials.

A 7-Eleven spokeswoman, Margaret Chabris, rejected the notion that the store on the corner of York Avenue and East 84th Street will bring down the neighborhood.

“We really take exception – we do not have rats in our stores,” said Ms. Chabris. She added that 7-Elevens now have daily fresh food deliveries and customize product offerings for each community. “We have changed the way we do everything. We just ask them to get to know us a little bit. A lot of our products are upscale and high-end.”

But for many Upper East Side residents, the issue is a larger one – the creeping homogenization of a city that takes pride in its one-of-a-kind, homegrown shops. Increasingly, national stores such as Banana Republic, Starbucks, Whole Foods, and Home Depot can be found throughout Manhattan.

“We have more and more chains all over the place,” a third-grade teacher, Penelope Sharrock, 23, said on a recent afternoon as she stood outside the still empty storefront that will house the convenience store. The site used to be a family shoe shop, then an independent video store with a large collection of foreign films.

A 7-Eleven will make the area “less of a family neighborhood,” Ms. Sharrock said. “It will feel more like strip mall America.”

For now, this stretch of York Avenue reflects the upscale tastes of the residents in the ivy-covered brick row houses that line the nearby streets. There are three small delis, along with an antique shop, a wine store, a florist, and several sidewalk cafes.

Several residents balked at the notion of an all-night store that sells beer, fearing it will attract transients and cause litter.

“I really do feel it’s incongruous with the nature of the neighborhood,” the vice president of the East 84th Street Neighborhood Association, Judy Cutler, said. “This block is more similar to living in some rural little community.”

It was the local bodegas that drove 7-Eleven out of Manhattan two decades ago. At the time, distribution problems prevented the chain from stocking fresh food every day, putting it at a competitive disadvantage with the city’s ubiquitous corner shops. The last 7-Eleven in Manhattan closed its doors in 1982, although the chain maintained its presence in New York’s other four boroughs.

In recent years, the franchise improved its distribution system and decided to make a foray back into urban centers. A fourth 7-Eleven is set to open up near Times Square by the end of the year, with several more Manhattan locations in the works for 2006.