A Lower East Side purveyor of challah, rugulach, and other Jewish specialties, Gertel’s will shut its retail store Friday, after nearly a century in business. The closure comes 18 months after the demise of the nearby Second Avenue Deli, and amid intense speculation that other historic eateries in the neighborhood could follow suit.

Gertel’s will continue to sell its signature sweets wholesale, the owner, Abraham Stern, said, noting that the baking would be done at a facility in Williamsburg, Brooklyn.

Mr. Stern recently sold the bakery building on Hester Street for $2.9 million, realestate records show. He said the buyer is a developer that intends to put up condominiums on the lot.

Mr. Stern, who has owned Gertel’s for 21 years, said the Lower East Side — once a haven for Jewish immigrants from Eastern Europe, and now peppered with bars, clubs, and music venues — no longer needs his kosher bakery. “We have people coming in crying,” he said. “But people who come down here can see the neighborhood, so they know why we’re closing.”

According to Mr. Stern, the bakery’s founder, Izzy Gerber, set up shop 93 years ago, renaming the bakery Gertel’s after he joined forces with his son-in-law several years later. The bakery has since changed hands twice, the proprietor said.

The chairman of retail leasing and sales at Prudential Douglas Elliman, Faith Consolo, said Lower East Side retail rents have tripled since last year. Businesses can now expect to pay $125 to $150 a square foot — up from $40 to $60 a square foot about a year ago, she said.

Ms. Consolo said the influx of residential construction has changed the Lower East Side landscape, and that residents are now hungry for the same range of businesses, such as pharmacies, dry cleaners, and home-improvement stores, available on the Upper East and Upper West sides.

As a result of the changes, neighbors yesterday said they fear Guss’s Pickles and Katz’s Delicatessen, other long-standing Lower East Side institutions, would be the next to close. Last month, the building where Guss’s is located was purchased for $16.5 million, according to PropertyShark.com, though plans for the property, at the corner of Orchard and Broome streets, are not yet known.

Meanwhile, an owner of Katz’s, Fred Austin, attempted to dispel swirling rumors that he would sell off the Houston Street space where the 119-year-old deli is located. “You never know what tomorrow brings, but my intention is to keep operating for many more years,” he told The New York Sun.

Mr. Austin, who grew up on the Lower East Side, said he would miss having Gertel’s nearby. “It’s always a sad day when an institution closes its doors, but I hope something new and exciting will take its place,” he said.

When there was a housing shortage, New Yorkers grumbled that there was nowhere to live, Mr. Austin said. “Now that they’re building housing, people are saying it’s forcing out small businesses,” he said. “Change is part of city life.”

A fourth-generation Lower East Side business owner, Niki Russ Federman, said she feared small, family-owned shops are an endangered species in the area. “Development has great economic implications,” Ms. Russ Federman, a partner in Russ & Daughters, a smoked fish and appetizer store that her great-grandparents opened more than 90 years ago, said. “At the same time, the things that made this neighborhood so iconic and filled with character are the victims.”

The family at the helm of Russ & Daughters owns the building that houses the store. “If we didn’t, maybe we wouldn’t be here either,” Ms. Russ Federman said.

Higher retail rents, coupled with a generational change in family businesses, make it difficult for mom-and-pop shops in the neighborhood to stay afloat, a director of sales at Massey Knakal Realty Services, Michael DeCheser, said.

“There’s Russ & Daughters, where the younger generation has stepped in and recognizes the value of hard work,” Mr. DeChesser, who specializes in Lower Manhattan, said. “But that’s a rarity, and more often than not the children choose not to follow in their family’s footsteps. The father may have a pickle factory, but the kids are doctors and lawyers.”

Gertel’s patrons yesterday lamented the store’s fate, even as some tried to understand it.

The bakery is a frequent stop on the walking tours led by guide Seth Kamil. “On one hand it’s terrible,” Mr. Kamil, 40, said. “On the other hand change has to happen. People aren’t eating all these things anymore; people don’t have time to come to bakeries.”

Buying two pounds of rugulach, and a challah loaf at Gertel’s yesterday, a Hunter College instructor, Daniel Simmonds, 46, said he was “crushed” to hear that the bakery was closing. “It’s the end of an era,” Mr. Simmonds, a 20-year patron of Gertel’s, said.