The owners of Gosman’s Dock Restaurant, a 477-seat eatery on Montauk Harbor, have placed 14 acres of developed and vacant land in Montauk on the market for $52.5 million.

The properties include six retail shops, four restaurants, three motels, two plots of vacant land, nearly an acre of beachfront on Block Island Sound and a 330-car parking lot.

The listing of the 11-property real estate portfolio stands out because of its size, industry experts said. “It’s one of the largest commercial transactions of its kind [on the East End] that I can recall,” said Jonathan J. Miller, president and chief executive of Miller Samuel Inc., a Manhattan-based commercial real estate appraiser and consultancy that does work on the East End.

Moreover, the sale could accelerate the spread of high-end restaurants and retailers in Montauk.

It’s “part of the pattern we’ve seen over the last decade” where marquee establishments in Montauk have been sold to outside developers and property investors, Miller said. “The East End has been a magnet for upscale restaurants and other facilities due to its linkage to the city, especially through the financial services sector.”

The Gosman family first bought the dock property in 1950 before acquiring additional properties in 1958. The family’s restaurant business started off as a chowder stand selling lobster rolls. The family, called at the restaurant, didn’t immediately return a request for comment.

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“The Gosman family is everything that’s right about Montauk,” said East Hampton Town Supervisor Larry Cantwell. “While it’s sad to see, since the Gosmans are so well thought of, there comes a time when an infusion of capital, in keeping with our zoning laws, is a natural transition.”

He added, “I would hope that anyone who purchases it would continue to operate it much in the same way it’s being operated today.”

Montauk has been trying to balance its growing popularity among trendy visitors with a family-friendly, low-key quality of life. During the summer, the hamlet’s population grows to as many as 30,000, versus a year-round population of 3,000.

In particular, the spread in recent years of young partygoers — whom residents accuse of drunkenness, public urination, bringing unwanted traffic — has sparked a backlash. This summer, visitors will see more police patrols, limits to crowd sizes at bars and restaurants, and other restrictions.

Southampton Town Supervisor Jay Schneiderman, who owns property in Montauk, said the potential sale of the Gosman’s properties might be welcome among many residents. He said he hadn’t heard many complaints from residents about the “upscaling” of Montauk.

“As much as Montauk has been struggling with the rowdy crowds, at the same time there’s been a movement of making Montauk a higher-end luxury destination,” said Schneiderman, former East Hampton supervisor and co-owner of the Breakers motel on Old Montauk Highway.

During the last 10 years, he said, higher property values have led many longtime business owners in the region to consider selling to developers or real estate investors.

One recent example: Trail’s End, said to be Montauk’s oldest restaurant, was sold in November for $2.15 million. The location will be fully renovated by the new owner, for a seafood restaurant to be named The Tauk at Trail’s End. Another example of change is the Montauk Beach House, a boutique hotel and beach club that opened in 2012, replacing the Ronjo Resort Motel, which served tourists for decades.

“The real estate values have gone through the roof and people are entering the real estate scene with a really strong ability to come in and invest sometimes millions to renovate a property,” Schneiderman said. “What we’ve seen in the last 10 years has been a fairly radical turnover of commercial properties.”

Miller said the Gosman’s properties would likely attract regional developers and wealthy individuals looking for “trophy investments.”

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Given East Hampton’s restrictive zoning and building codes, whoever purchases the property will have limitations on expanding the size of the properties or changing their use.

“This is a property offering that’s about redevelopment but not gross changes,” said Julia Prince, exclusive listing agent with Saunders & Associates, the Hamptons brokerage marketing the property. She said “the right buyer” would have “an understanding of the complexities and the wonderful things this community represents.”