Two nonprofits that have worked together to promote soccer in the United States are getting a divorce, with custody of the name “U.S. Soccer Foundation” in the balance.

The United States Soccer Federation Foundation Inc. sued the United States Soccer Federation Inc. on Thursday, seeking a declaration of rights over the name U.S. Soccer Foundation.

The foundation says it's been using the name to support youth soccer in the United States, particularly among disadvantaged kids, for more than 20 years. But the federation—the governing body that oversees the U.S. national teams and world-class competition—registered the name with the U.S. Patent and Trademark Office in the late 1990s and recently told the foundation to stop using it.

That led to Thursday's complaint, filed in the District of Columbia by Quinn Emanuel Urquhart & Sullivan. It alleges the groups have “co-existed peacefully” while the foundation raised more than $100 million for soccer pitches, uniforms and equipment.

Now the Federation has “threatened to hijack the foundation's trademarks for its own use—likely in an effort to capitalize on lucrative business opportunities when the United States hosts the World Cup in 2026,” according to the complaint, which is signed by Quinn D.C. associate Scott Lerner. Quinn New York partners Robert Raskopf, Todd Anten and Julia Beskin are also on the complaint.

The foundation describes itself as the major charitable organization of soccer in the United States. It was set up with $50 million in surplus funds from the 1994 World Cup. Since then it's used the U.S. Soccer Foundation name on fundraising material sent to prospective donors, on kids' soccer jerseys, on its website and social media pages and on the surface of pitches across the country, according to the complaint. The organization says it raised $18 million in the last year alone.

The complaint acknowledges that the federation is listed as the owner of the U.S. Soccer Foundation marks. But, it contends, the two organizations “have shared the understanding that the foundation is the actual owner.”

The governing federation operates its own U.S. Soccer Development Fund. The complaint alleges that the federation hasn't used the U.S. Soccer Foundation mark in at least the last three years, if ever. But the federation has “recently and abruptly done an about-face, demanding that the foundation cease using the Foundation Marks and indicating an intention to use them in the future.”

The complaint seeks a declaration of non-infringement, an order canceling the federation's registrations and an award of damages for unfair or deceptive trade practices.

Lawrence Siskind, a trademark attorney at Coblentz Patch Duffy & Bass who's not involved in the case, said a key issue is likely to be abandonment. If there is indeed no evidence the federation used the marks over the last three years, that could create a legal presumption that the marks have been abandoned. “It can be rebutted,” he said, “but the longer the time period that's gone by, the harder it is to rebut.”