The Big East sued TCU for failing to pay the conference $5 million after the school reneged on an agreement to become a member and chose to join the Big 12 instead.
The Big East filed the lawsuit Monday in U.S. District Court in Washington.
TCU agreed in November 2010 to join the Big East, beginning this July. The Big East contends TCU agreed to pay the league $5 million if it did not follow through on that agreement.
In October 2011, TCU accepted an invite to the Big 12.
In the lawsuit, the Big East says it has ''made demand for the payment owed under the Agreement, but TCU has refused to make that payment or acknowledge its obligation to do so.''
''TCU administrators were surprised by this lawsuit and believe it is premature. The University is hopeful for an amicable resolution of this matter,'' the school said in a statement. ''Because of the pending litigation, TCU will have no further comment.''
TCU is leaving the Mountain West and will become a member of the Big 12 in July.
Big East spokesman John Paquette said in an email to the AP the league had no further immediate comment.
The Big East settled in February dueling lawsuits with West Virginia, which is also joining the Big 12 in July. The Big East received $20 million and West Virginia was allowed to leave the conference before the end of the 27-month notification period required by the league's bylaws.