New York, New York - NFL owners on Tuesday voted to allow private equity investment in a landmark move that could see billions of dollars in new funding pumped into football, the league confirmed.

At a meeting in Milwaukee, the owners of the NFL's 32 teams gave the green light to a plan that would allow a group of hand-picked private equity firms to purchase up to a 10% stake in a team.

Tuesday's vote represents a significant departure for the way NFL teams are funded. Historically, franchises have been run as family businesses or owned by wealthy individuals.

The move to allow private equity investment potentially puts billions of dollars of new cash on the table to help pay for new stadiums and other projects.

According to NFL documents setting out the parameters of the new funding deal, private equity firms can now purchase up to a 10% stake in a team and must retain that investment for a minimum of six years.

The NFL has approved three private equity firms, Arctos Partners, Ares Management, and Sixth Street, as well as a consortium consisting of Blackstone, Carlyle, CVC, Dynasty Equity and Ludis, as the companies allowed to invest in the NFL.

NFL Commissioner Roger Goodell told a press conference following Tuesday's vote that the funding measure would barely be noticed by NFL fans.

"From a fan's standpoint, this won't change a thing," Goodell said.

"This is 10% of a team. All it is is a silent position that would give access to capital for the teams that wish to offer 10% of their teams."

But critics of the move pointed out the new agreement allows private equity firms to own stakes in multiple teams, as well as NFL owners to have investments in companies that could then buy into rival organizations.

The decision brings the NFL into line with other US sports leagues, as well as some of the world's biggest soccer teams.

The MLB, NBA, and NHL allow up to 30% of teams to be owned by investment firms.

Sixth Street has already invested in Spanish soccer giants Real Madrid's new stadium and also owns a stake in the San Antonio Spurs. Another of the approved NFL investors, Dynasty Equity, owns a stake in the Premier League's Liverpool.

Goodell emphasized that private equity firms investing in the NFL would have no say in how teams operated or how the league was run.

"They will not be in any kind of decision-making influence in any way," Goodell said.

Reports have said the NFL will not, however, allow sovereign wealth funds – such as Saudi Arabia's Public Investment Fund worth around $925 million – to invest in its teams.