The $58 million sale of Seattle Reign FC to a new ownership group that includes MLS' Seattle Sounders FC is finally complete.

The Reign, along with former French owners OL Groupe, announced the news on Monday.

The Sounders are joined by private equity firm the Carlyle Group in the new ownership group. Carlyle Group is investing more than 50% of the joint venture, but the Sounders were "instrumental" in getting the deal done, said Alex Popov, Carlyle's head of private credit.

The $58 million price tag is a dramatic increase in valuation of the team. OL Groupe bought the Reign for about $3.5 million in late 2019.

"It's all about the potential going forward," Popov told ESPN. "And frankly, our starting point was off. You know, that's what attracted a lot of us to, including ourselves here at Carlyle, to think about investing in women's sport. We have seen the potential."

Team valuations have grown exponentially across the NWSL recently. San Diego Wave FC, which first joined the NWSL as an expansion team in 2022, is in the process of a two-part transaction that values the team between $113 million and $120 million.

NWSL commissioner Jessica Berman said last year that she hoped the sale of the Reign would close around the new year. OL Groupe previously announced the deal in March, but exact details of the new ownership group were not shared.

The Reign's sale to a group that includes the Sounders finally gives Seattle's NWSL side a sense of true stability in the Emerald City. The Reign have won three NWSL Shields since the club's inception in 2013, but the team has historically struggled to find its footing off the field.

Seattle previously played at Memorial Stadium downtown, but uncertainty around the venue's future at the end of 2018 put the Reign's future in the market in doubt.

The team moved to Tacoma in 2019 and removed "Seattle" from its name.

Less than a year later, OL Groupe, which owned the successful Lyon women's side at the time, bought a majority stake in the Reign and the team was rebranded as OL Reign. The team made Lumen Field its permanent home in 2022 and averaged crowds of 13,610 fans per game in the 68,000-plus seat stadium last year.

Maya Mendoza-Exstrom, who spent 10 years with the Sounders and will now serve as the Reign's chief business officer, said Lumen Field is unequivocally the Reign's home.

"It feels a little bit like we have the gritty startup mentality of an expansion franchise in this exciting moment, but we have this benefit of having a dedicated fan base that has been dedicated to this club, even though it has moved a ton and changed a ton over the last few years," she told ESPN. "So, I think the opportunity just to root this club in place -- Lumen is our home. The club's not moving anywhere."

Filling the lower bowl of Lumen Field consistently is a realistic target for the Reign, but Mendoza-Exstrom and Popov both understand that what works for the Sounders might not be the right approach for the Reign. The Sounders averaged over 32,000 fans per game last year.

"We'll figure out where our gaps are, and we'll figure out where our synergies are, and then we will invest in the resources," Mendoza-Exstrom said. "And that includes human resources to make sure that the Reign are resourced in a way that's commensurate with what we need to do to grow. And that could be any number of human beings, that could be technology, that could be facilities. It's all on the table."

The Reign's new ownership structure formally unifies Seattle's MLS and NWSL teams after over a decade of operating independently. Sounders owner Adrian Hanauer became a minority owner in the Reign upon the team's move to Tacoma, but exited when OL Groupe bought the team. Hanauer will now be part of the Reign's ownership group again and serve as governor on the NWSL board, with Popov as the alternate.

"Today is a milestone day for soccer in our city and I am humbled to be a part of it," Hanauer said in a statement. "This announcement is about keeping one of the top women's teams in the world locally rooted in our community for generations of fans to enjoy."