Light heavyweight titleholder Beibut Shumenov announced Thursday that he filed a lawsuit against Goossen Tutor Promotions in Nevada court.
Shumenov terminated his promotional agreement with Goossen Tutor in January and is seeking to have the court uphold the termination.
Shumenov accused Goossen Tutor of violating various duties under the contract. He charged breach of contract, breach of fiduciary duty, fraud and deceptive trade practices. He also is seeking unspecified damages, including punitive damages.
Promoter Dan Goossen said he would fight the lawsuit.
"We have a valid and enforceable contract and will pursue our legal rights, and have formally informed Shumenov, advising him of that," Goossen said.
Shumenov's own promotional company, KZ Event Productions, worked with Goossen Tutor on his last two fights.
In those two bouts, Shumenov defended his belt against Vyacheslav Uzelkov via unanimous decision last July in Lemoore, Calif., and in January scored a sixth-round knockout of last-minute replacement William Joppy in Shumenov's native Kazakhstan.
Shumenov (11-1, 7 KOs), who had made three title defenses, was a 2004 Kazakhstan Olympian who now lives in Las Vegas.
Dan Rafael covers boxing for ESPN.com. Follow him on Twitter.