NFL owners have approved new ownership rules that will allow private equity firms to buy passive minority stakes in franchises, according to someone with direct knowledge of the process.

Owners voted Tuesday afternoon during a gathering in Minnesota, said the person, who was granted anonymity because the details are private. The move follows years of speculation and months of targeted discussion about how the world’s richest sports league might make it easier for owners to offload small minority stakes. The final count for approval was 31-1, with the Cincinnati Bengals the lone dissenting vote.

Under the new NFL policy, teams can sell up to 10% of their common equity to PE firms, according to a summary shared by the league. A firm can buy as much as 10% of a team, or little as 3%. No single fund can invest in more than six teams, and the minimum hold period for each investment is six years. Funds must have at least $2 billion in committed capital, and no one team can represent more than 20% of a single fund.

The decision will likely allow a handful of PE firms to buy equity from owners who wish to sell. The firms involved in late-stage discussion over the past few weeks are Arctos Partners, Ares Management and Sixth Street; and a consortium of Blackstone, Carlyle Group, Luxembourg-based CVC, Dynasty Equity and Ludis, a platform founded and led by retired NFL Hall of Famer Curtis Martin.

There are likely other provisions beyond those shared initially by league, ones that give even more favorable terms to NFL owners. As Sportico previously reported, the league was considering a provision that would allow the NFL to buy back stakes within a certain period of time if owners decided to reverse course. According to CNBC, the NFL was also looking to take a percentage of profits on sales down the line. For now, though, the PE firms are looking at the upside ahead.

“Ares is honored to have been accepted by the NFL to be able to invest in its iconic football franchises,” an Ares Management spokesperson said in a statement. “We are excited for the opportunity to support the continued growth of NFL teams through Ares’ extensive investment experience and strong relationship networks in the sports, media and entertainment sector.”

Arctos Partners said that, if finalized, it would be the only firm to invest in equity across the five most popular North American leagues. “While there is much work ahead, today is a milestone reflecting Arctos’ commitment to the sports industry, our position as the market innovator and passion for being the partner of choice for leading sports ownership groups,” Arctos said in an email. “We thank the NFL for its trust and look forward to contributing to the League’s continued success.”

The move makes the NFL the last of the major U.S. pro league to allow institutional investors. It’s believed term sheets for at least a handful of deals have already been prepped in anticipation of approval. The average NFL franchise is worth nearly $6 billion, according to Sportico‘s numbers.

(This story has been updated with a details and quotes throughout.)