NFL owners passed a new policy that will allow them to sell up to 10% of their teams to a select group of preapproved private-equity firms, opening the spigot for billions of dollars to flow into the league.

NFL owners passed a new policy that will allow them to sell up to 10% of their teams to a select group of preapproved private-equity firms, opening the spigot for billions of dollars to flow into the league.