The NWSL announced on Friday that it has extended its partnership with Nike through a historic, long-term agreement.

The deal represents the the most substantial agreement in NWSL history, expanding upon and representing Nike’s “significant commitment to the sport, the NWSL and its players and clubs,” the league said in a press release. The extension builds on the partnership the two organizations began nearly a decade ago with the formation of the league in 2013.

“Since the beginning, Nike and the NWSL together have driven significant growth of this great game for all, in the U.S. and around the world, and we couldn’t be more excited to extend this foundational partnership well into our second decade of play,” said Marla Messing, NWSL interim CEO. “With this agreement, Nike is showing the world again what it means to support athletes, helping to grow the opportunities available for them to compete, and supporting the NWSL and its athletes in its effort to remain the premier destination for the world’s most elite players.”

As part of the partnership, Nike will focus on elevating the sport’s performance through research into footwear and apparel innovation. The sides also aim to grow NWSL engagement by highlighting athletes on and off the field.

“Nike continues to champion long-term change in women’s sports,” said Becca Kerr, Nike VP and GM of North America Women’s. “Our ongoing partnership with NWSL and our continued investments in soccer through partnership and grassroots efforts are catalyzing action and progress to help drive that change.”

The league is in the process of completing its ninth season, culminating in the NWSL Championship between the Washington Spirit and the Chicago Red Stars on Saturday.