A legal battle is unfolding at the American Airlines Center as the Dallas Mavericks file suit against the Dallas Stars, claiming the hockey team violated a long-standing lease agreement that governs their shared home arena.

According to The Dallas Morning News, the Mavericks filed a petition alleging that the Stars breached a clause in their agreement that requires both teams’ headquarters to remain inside the city of Dallas. The Stars have operated out of Frisco since 2003.

The lawsuit is the latest development in growing tensions between the two franchises over the future of the American Airlines Center and a potential $300 million renovation deal that could extend both teams’ leases at the arena through 2061.

The Mavericks say the Stars backed out of that long-term extension. The Stars, meanwhile, contend that they agreed to a different deal that would keep both teams at the arena through 2035.

The Mavericks and Stars have shared the American Airlines Center since it opened in 2001. Under their current agreement, both franchises could leave after the lease expires in 2031.

Representatives from both organizations have not publicly commented beyond confirming the legal filing.