Texas Christian University, which had already pledged to join the Big East conference, will instead join the Big 12 athletic conference, officials announced Monday, latest in a series of college sports realignments.

I am fired up, said an emotional Chris Del Conte, TCU athletic director, addressing student athletes in a boisterous news conference on the TCU campus in Fort Worth, Texas, on Monday night. Today is living proof that dreams do come true because of your efforts.

Trustees voted unanimously on Monday afternoon to accept the invitation, which comes just weeks after Texas A&M announced plans to leave the Big 12 and join the SEC.

The schools will make the switch before the start of the 2012-13 season.

Joining the Big 12 brings us back to share a rich tradition with a lot of schools we already have natural rivalries with, said TCU chancellor Victor Boschini. It connects us also with schools that are committed to the same academic success that we are.

The move comes after the Horned Frogs had already committed to joining the Big East conference for next year. By bolting from the Big East before officially joining, TCU owes a $5 million exit fee, Del Conte said, though they will not have to wait the required 27 months before leaving. TCU was scheduled to join the Big East on July 1.

A former member of the Southwest conference in the days before it disbanded in 1996, TCU had been a member of the Mountain West conference for the past six years. When the Big 12 was formed in 1996 with several former SWC members, TCU was not among them.

I'd like to welcome you home, Big 12 interim Commissioner Chuck Neinas told TCU leaders on Monday.

Though the basketball and baseball programs were celebrated as instrumental to the Big 12 invitation, Del Conte gave most of the credit to the success of the football team. It was the only one in the nation to be ranked in the top 10 by the Associated Press and USA Today for three years in a row, officials said.

The school is also completing a $164 million renovation of the Amon G. Carter Stadium in time for next season, with a new seating capacity of 50,000.

The Mountain West has been a great home to TCU, enabling our athletics program to grow and be in position to receive and accept an invitation to join the Big 12, Del Conte said. We are also appreciative of the Big East for providing an opportunity for TCU.

As is the case with several conferences, the Big 12 has been dealing with a shake-up in recent weeks. The Big 12 is still waiting for a commitment from the University of Missouri as to whether it will stay in the conference.

Colleges are scrambling in pursuit of lucrative television broadcast contracts. At stake are billions of dollars of royalties from networks such as ESPN and FOX Sports for broadcasting popular college football games.

Sports economists say being part of a powerful conference is vital to a university, which is why colleges across the nation are nervously watching the musical chairs.