The longtime owners of Starrett City, the sprawling Brooklyn housing complex overlooking Jamaica Bay, are selling the development for more than $850 million, and among those who stand to benefit is President Trump, a partial owner.

Starrett City is the largest federally subsidized housing development in the country, and the sale will require the approval of the federal Department of Housing and Urban Development and state housing officials, raising potential conflicts of interest for Mr. Trump and his family. Mr. Trump owns a 4 percent stake in the complex, according to his federal financial disclosure forms; other members of the Trump family also own stakes in the partnership.

The buyer is a joint venture of the Brooksville Company, a recently formed residential real estate firm, and Rockpoint Group, a private equity firm that invests in real estate. The pending deal, which is expected to close early next year, was announced to tenants, employees and elected officials on Wednesday.

Representatives Hakeem Jeffries, whose district includes Starrett City, and Elijah E. Cummings, a member of the House Committee on Oversight and Government Reform, highlighted the potential conflict of interest in July when rumors circulated in New York that Starrett City would be refinanced.