BusinessmanDean Metropoulos,known in business circles for reviving troubled consumer brands, has an agreement to buy a 5 percent stake in the team, while the second deal, for a 3 percent stake, is with the Sixth Street investment firm, which recently bought into the NBA’s Boston Celtics ownership group.Sports Business Journal was first to report news of the deal.

Terms of the two transactions were not disclosed. But based on a valuation of at least $9 billion, Metropoulos’s 5 percent stake would equate to at least $450 million, while Sixth Street’s at least $270 million. And the Patriots get a huge infusion of money without the Kraft family having to give up control of the jewel of its suite of businesses.

“The Kraft family remains fully committed to long-term ownership and operational control of the Patriots,” the team said in a statement.

The deals are expected to be voted on by NFL team owners at league meetings in October.

If approved, they would mark the second-richest valuation of an NFL team, with the New York Giants selling 10 percent of their team this month at a valuation of more than $10 billion.

Robert Kraft purchased the Patriots in 1994 for $172 million. From 2001-18, with Tom Brady at quarterback and Bill Belichick as coach, the franchise began an unprecedented period of domination, appearing in nine Super Bowls and winning six. The run of success, along with the construction of Gillette Stadium and its adjacent retail space, Patriot Place, elevated the Patriots to near the top of the list of the NFL’s most valuable franchises.

The personal wealth of Kraft, chairman and CEO of the team, and the Kraft Group, grew alongside the team’s. Forbes estimated his fortune at $13.8 billion, third highest in Massachusetts, 78th highest in the United States.

The transaction will not include the family’s ownership of the New England Revolution of Major League Soccer.

Metropoulos, who holds an undergraduate degree and an MBA from Babson College in Wellesley, heads the family-owned Metropoulos & Co. investment firm, whose turnaround projects include the Pabst Brewing Company and Hostess Brands.

The ballooning value of NFL teams — the lowest ranked by Forbes Magazine is the Cincinnati Bengals at $5.25 billion — prompted the league to allow private-equity firms into its ownership ranks years after the other North American professional sports leagues allowed outside investment firms to help owners shoulder costs in the seemingly recession-proof industry.

Last summer,the NFL approved Sixth Street and three other private-equity entities as potential investors, but limited their investments to passive, noncontrolling stakes of between 3 and 10 percent and a holding period of at least six years. Investors can buy into more than one NFL team.

To date, the Arctos Partners investment firm owns stakes in the Buffalo Bills and Los Angeles Chargers, while Ares Management owns a stake in the Miami Dolphins.

George Pyne, whose firm Bruin Capital invests in sports and media companies, said it made good business sense for the Krafts to capitalize on the huge appreciation in the value of their investment in the Patriots.

“It’s hard not to do what they did,” said Pyne, a native of Milford whose father played for the Boston Patriots in 1965. “You can take that capital and you can deploy that capital in a constructive way. If you still own 92 percent of the Patriots and have a small amount of diversification and can allocate capital against other strategies or investments, it’s probably a really good idea and a really smart thing to do.”

The Patriots did not elaborate on their plans for the new capital, but possible targets include upcoming significant long-term player contracts. The team spent $250 million two years ago on a renovation of the north end of Gillette Stadium.

In a statement, the Patriots described Metropoulos as “a seasoned entrepreneur and founder of Metropoulos & Company, a prominent family-owned investment firm known for its transformative acquisitions.”

The Patriots also said Sixth Street’s investment “reflects its continued commitment to partnering with the world’s premier sports franchises and its confidence in the New England region as an engine for economic growth.”

A spokesperson at Sixth Street, which has a Boston office and is headquartered in San Francisco, declined to elaborate beyond the team’s statement.

The Patriotsinvestment marks the firm’s first in an NFL team. It owns shares in the new Bay FC National Women’s Soccer League team, Major League Baseball’s San Francisco Giants, and two of Spain’s top-tier soccer teams, Barcelona and Real Madrid.

Sixth Street also has a little more than 10 percent of the newownership consortium led by Bill Chisholm that purchased the Celtics this year for $6.1 billion.

During a news conference Thursday on his ownership of the Celtics, Chisholm spoke of Sixth Street’s role in his own deal, stressing the firm was not trying to be active owners of the franchise.

“They’re folks that I’ve done business with in the past, they were instrumental in filling out the support for the deal, and I think that, really importantly, they are definitely behind the scenes,” said Chisholm. “They’ve been great partners for us. I can’t say enough about them. But at the end of the day, they’re in the background.”

Nicole Yang of the Globe staff contributed to this report.

Michael Silverman can be reached atmichael.silverman@globe.com.