Mayor Zohran Mamdani and a citywide network of tenants have opened a new front in a fight to block the sale of more than 5,000 rent-stabilized apartments from a bankrupt landlord to a company they say has a checkered ownership history — this time enlisting the support of New York Attorney General Letitia James.

The top housing official in James’ office on Monday filed documents in court supporting the city’s latest objection to the looming bankruptcy sale of 93 deteriorating apartment buildings owned by real estate firm Pinnacle. The filing comes days after the company Summit Properties USA bid $451 million for the buildings.

Brent Meltzer, the head of the attorney general’s housing protection unit, told the court that James supports the city’s efforts to delay the sale due to “significant concerns” about Summit’s ability to maintain its existing portfolio of rent-stabilized apartment buildings.

In court papers, Meltzer described how Summit’s 3,000 current apartments have more than 4,000 open housing code violations, mirroring the dangerous conditions that Pinnacle tenants have long faced in their apartments. A citywide network of tenants organized after Pinnacle declared bankruptcy last year in an effort to steer the sale to a purchaser who they say would be more responsible.

Meltzer also highlighted Summit’s business links with real estate firms Chestnut Holdings and Denali Management. A Gothamist analysis found Chestnut executive Jonathan Wiener, brother of Pinnacle CEO Joel Wiener, signed more than 50 deeds and loan documents for buildings currently listed on Summit’s website.

The attorney general sued Chestnut, Summit’s partner, for lead paint violations at its buildings in 2020. The firm later agreed to pay $300,000 in penalties. Executives for Chestnut and Denali have appeared on the public advocate’s list of “worst landlords” based on conditions in buildings they own and manage with Summit as recently as last year.

Meltzer urged federal bankruptcy Judge David Jones to halt the sale, or “at least require Summit to provide a much more detailed explanation about how it intends to reverse its history of purchasing buildings that accrue high levels of violations,” as well as what management company it intends to hire to run the Pinnacle buildings.

A confirmation hearing for the pending sale is scheduled for Thursday.

Summit spokesperson Jordan Barowitz said Chestnut and Denali are not involved in the deal to acquire Pinnacle properties and the company will soon file new documents describing its plan to correct the thousands of outstanding violations in the buildings.

“Summit is ready to work with the city, [the Department of Housing Preservation and Development] and the residents to improve and preserve this much needed affordable housing,” Barowitz said. “Delay will only slow the opportunity to make improvements that benefit the residents.”

The company told Gothamist on Monday that the bankruptcy process reduced debt on the Pinnacle buildings by $275 million, freeing up money that Summit can use to invest in repairs and maintenance.

In an unsigned email, a representative for Denali said the company attempts to address all complaints from tenants as soon as they arise and is not involved with the bid for Pinnacle’s properties. Chestnut did not immediately respond to requests for comment on the attorney general’s accounting of their ownership practices and poor condition of their buildings.

In a separate filing late Monday, city attorneys also questioned “Summit’s current track record as a landlord,” as well as “the possibility that a potential connection” between Pinnacle and Summit was not disclosed.

City lawyers told the judge the reporting on Summit’s close business ties to the brother of Pinnacle’s CEO raises “the question of whether the purchaser is an insider” subject to more scrutiny. They asked the court to require a deeper review of the connections.

Spokespeople for Pinnacle’s lender, Flagstar Bank, have not responded to requests for comment about the real estate firm’s bankruptcy, the pending purchase by Summit or the latest objections. Documents submitted in court late last year show the Summit bid was dependent on Flagstar’s approval.

Jones, the bankruptcy judge, last week denied the Mamdani administration’s request to delay the sale in order to give tenants and housing officials more time to find another potential purchaser. City lawyers say the city has special interest in the transaction because it is a substantial creditor owed nearly $13 million in unpaid fines.