The financial transaction was closed at 12:30 p.m. Wednesday, the team announced in a statement. That came a day after Mikhail Prokhorov's purchase of the team was approved by NBA's owners, who welcomed the first non-North American into their club.
Russia's richest man agreed to buy 80 percent of the Nets and 45 percent of an arena project in Brooklyn from developer Bruce Ratner late last year. Final approval of the sale was delayed until the state of New York had taken over all the land seized under eminent domain at the site of the team's Barclays Center in Brooklyn.
The long-delayed 18,000-seat arena should open in 2012.
"This much-anticipated day has finally come and now the real fun begins of building a championship team with a state-of-the-art home in the Barclays Center at Atlantic Yards," Prokhorov said. "It's a wonderful opportunity to combine great sports and good business, and I look forward to working with Bruce Ratner and Forest City and with the Nets organization as we move ahead.
"To the fans, whether in New Jersey, Brooklyn, or Moscow, I will do everything I can to give you a winning team. See you at the draft lottery."
The Nets hope Prokhorov's wealth — estimated at $9.5 billion through his banking and metals businesses — will be used to help them bounce back from a 12-70 finish that included an NBA-worst, 18-game losing streak to open the season.
The team was ruined by cost-cutting moves under Ratner, who signed off on the trades of Jason Kidd, Kenyon Martin, Vince Carter and Richard Jefferson. There's money to spend now, with an estimated $23 million in salary cap room heading into free agency this summer, when LeBron James, Dwyane Wade and Chris Bosh are among the players who could be available.
Prokhorov already has proven he can build a winning basketball team, owning a share of European power CSKA Moscow.