Marshall University filed a lawsuit against Conference USA on Tuesday to speed up its move to the Sun Belt Conference, the Division I conference that the university plans to join by the summer.

The lawsuit was filed in response to Conference USA’s demand for arbitration in Dallas after Marshall announced last year that it would join the Sun Belt. The move makes Marshall the third school to join the conference amid months of shuffling among N.C.A.A. universities in an era of realignment that has shifted the college sports landscape.

Marshall is one of several N.C.A.A. schools publicly feuding with its conference in response to the latest shuffles, including a big move last year by Texas and Oklahoma to leave the Big 12 for the Southeastern Conference.

Earlier this month, Marshall, Old Dominion and Southern Mississippi announced that they would leave Conference USA at the end of the 2021-22 academic year, on June 30.

According to the league’s bylaws, member schools must give 14 months’ notice before leaving the conference, which means the universities would have needed to notify it in May 2021 in order to exit in July 2022. In a statement on Feb. 11, Southern Mississippi said the league has refused to negotiate terms of an early exit.

“The conference’s unwillingness to discuss the concept of separation this year creates confusion and doubt for all concerned,” Southern Mississippi said. “The remaining members of Conference USA deserve certainty about their schedules as they plan for competition next year.”

According to the lawsuit, Marshall first notified Conference USA of its intention to withdraw from the league on Nov. 1, 2021. It notified the league three more times in January, specifying that it planned to end its membership on July 1, 2022, and requested not to be put on any of the league’s athletic schedules in the fall.

Conference USA released its 2022 football schedule last week, and included Marshall, Old Dominion and Southern Mississippi, stating that the league intends to move forward with all 14 of its members.

The league said in a statement that it will “exhaust all necessary legal actions” to make member schools abide by their contracts.

Conference USA did not immediately respond to a request for comment on Thursday.

Marshall is seeking to resolve the lawsuit in court in its home county in West Virginia rather than in arbitration, the preferred forum of the league. The university said in its lawsuit that when Marshall signed its agreement to become a member of Conference USA in 2003, there was no language in the bylaws that required arbitration if a member school decided to leave the conference.

When asked why Marshall was trying to expedite its departure from Conference USA, Jason Corriher, the university’s assistant athletic director for media relations, provided a statement citing “the best interests of Marshall’s student-athletes and its loyal fans.” The statement added that the university wanted to find an amicable resolution but the conference has refused attempts at discussion.

The lawsuit, Marshall said in a second statement, is “the beginning of litigation intended to protect our rights, help us reach an agreement in a timely manner and clear the way for our shift in conference affiliation.” Corriher said the school has no desire to speak further about the lawsuit.

The Sun Belt declined to comment, referring instead to Marshall’s public statements.

Stony Brook (America East Conference), the University of Illinois at Chicago (Horizon League), and James Madison (Colonial Athletic Conference) all decided to leave their respective leagues beginning in the 2022-23 academic year.

In response, the conferences prohibited the universities’ teams from participating in all conference team championships, invoking existing league bylaws that make a school’s sports teams ineligible to participate in the postseason once a member institution intends to withdraw from the conference.

It is the latest example of the bitterness of conference realignment, one in which the student-athletes that have been barred from competing feel the most severe consequences of the contractual disputes.

Last week, Stony Brook, the University of Illinois at Chicago and James Madison released a joint statement asking that the conferences eliminate membership transition provisions that directly impact student athletes.

“Student-athletes around the country have admirably navigated the physical and mental toll of the past two, pandemic-impacted years,” the statement said. “No conferences should impose participation penalties that inflict additional, unnecessary harm.”