Nets owner Forest City Ratner finalized an agreement Wednesday with Russian conglomerate Onexim, owned by billionaire businessman Mikhail Prokhorov.
The deal creates a partnership for the development of the Atlantic Yards project and the Barclays Center.
Prokhorov's company will now own 80 percent of the Nets and 45 percent of the arena, with an option to buy up to 20 percent of the Atlantic Yards project.
The sale of the Nets is subject to approval by the NBA Board of Governors.
The agreement comes a day after Forest City Ratner announced that $511 million in tax-free bonds for the arena were sold.
Opponents were hoping the bond sale would fall flat and kill the project.
Last month, the New York Court of Appeals ruled the state can use eminent domain to force the sale of businesses and residences to make way for the nearly $5 billion project.