Three more Pac-12 schools are on the move to the Big 12.

The Big 12 announced late Friday that it has added Arizona, Arizona State and Utah to the conference, effective in 2024.

With the three additions, the Big 12 would grow to 16 members for 2024. Colorado previously departed the Pac-12 for the Big 12 last week and the conference added BYU, Cincinnati, Houston and UCF after Oklahoma and Texas departed for the SEC.

"We are thrilled to welcome Arizona, Arizona State and Utah to the Big 12,” Big 12 commissioner Brett Yormark said. “The conference is gaining three premier institutions both academically and athletically, and the entire Big 12 looks forward to working alongside their presidents, athletic directors, student-athletes and administrators."

The Arizona Board of Regents — which oversees both Arizona and Arizona State — recommended the move to the Big 12 in a meeting on Thursday night, opening the door for the Big 12 to accept formal applications from those two schools. Utah submitted its own application on Friday afternoon and its board met hours later to cement the move with a vote.

Big 12 executives met Thursday to approve an application for Arizona to join the league. Arizona State and Utah were not as bullish about leaving the Pac-12, but things changed Friday after Oregon and Washington received invitations to join the Big Ten.

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Arizona and Arizona State have been members of the Pac-12 since 1978. They were founding members of the old Western Athletic Conference before they left to turn the Pac-8 into the Pac-10. Forty-five years later, the two are set to make another conference move together.

"Arizona Athletics is positioned well for long-term success, as our goal always was to secure a bright future for our student-athletes, fans, and the entire university community," Arizona president Robert Robbins said. "Our move to the Big 12 conference will continue to raise the University’s profile by increasing visibility, growing our reach across the country and around the globe, expanding our pool of prospective students, providing more resources to support our student-athletes, and presenting them with greater NIL prospects."

"We are excited for this new chapter, a move that is necessary to remain competitive in top-tier Division 1 athletics," said ASU President Michael Crow. "We are joining a premier athletic conference and bringing with us programs on the rise, our rich traditions and history, and the metro Phoenix media market. We're in a good spot, and we are pleased to be with UArizona and Utah in the move."

Utah, meanwhile, is moving conferences for the second time in 12 years. Like Arizona and ASU, Utah was a founding member of the WAC and stayed in that league until 1999. From there, the Utes were members of the Mountain West until they joined the Pac-12 in 2011.

"I am very enthusiastic about the University of Utah's future within the Big 12. Joining our Pac-12 and Association of American Universities peers from Colorado and Arizona is important to our mission and makes sense, as does, renewing our historic in-state rivalry with Brigham Young University," said Utah president Taylor Randall. "Being part of the Pac-12 has elevated the University of Utah and demonstrated our student-athletes can compete at the highest levels on and off the field, our move to the Big 12 will not change that position."

Arizona, ASU and Utah will be the sixth, seventh and eighth schools to leave the Pac-12 in the last 13 months. Last July, UCLA and USC accepted invitations to the Big Ten, effective in 2024. Colorado then started the latest wave of realignment last week before Oregon and Washington bolted for the Big Ten on Friday.

With the Pac-12 on the verge of collapse, the three schools opted for the security of the Big 12.

Why are schools leaving the Pac-12?

The Pac-12 has been on shaky ground since the defections of USC and UCLA. The conference has been desperately attempting to land a new media rights deal for the last year. All the while, the Big 12 — which already extended its media rights deals with ESPN and Fox through 2031 — has aggressively pursued expansion candidates.

As of last week, the Pac-12’s presidents and chancellors had yet to be shown any financial figures regarding a new media rights deal by commissioner George Kliavkoff. The uncertainty proved to be too much for Colorado to withstand, and the school made the leap for the security of the Big 12.

The Pac-12’s presidents and chancellors were finally presented with the details of the media rights deal on Tuesday. The deal featured the streaming platform Apple as the primary rights holder with potential sub-licensing opportunities to linear television entities like ESPN and Fox. The Pac-12’s current TV deal with ESPN and Fox expires next July.

When Colorado officially departed, school officials pointed to the visibility and reach provided by the Big 12’s TV deal as a preferable option. The Big 12’s deal would also provide a larger revenue share than the Pac-12’s.

“Fox and ESPN is who we want to be aligned with,” Colorado AD Rick George told reporters last Thursday at a news conference in Boulder.

George also said the Big 12 would provide “more favorable time slots” and “greater national exposure” than remaining in the Pac-12.

Randall, the Utah president, said Friday that "stronger forces" in college athletics and the "greater media landscape" ultimately brought the Utes to the decision to leave the Pac-12.

"I am grateful for all of the hard work my Pac-12 conference colleagues invested in an effort to find solutions to keep the conference whole and provide a pathway forward to benefit all of our students, fans and communities. Ultimately, stronger forces within national collegiate athletics and the greater media landscape brought us to today's decision. I am hopeful the relationships we have made over the past 12 years within the Pac-12 remain strong," Randall said.

Added Utah athletic director Mark Harlan: "After very thorough and comprehensive efforts to preserve our present conference affiliation in the aftermath of the announced departures of UCLA and USC last year, we have explored all options and have determined that the right path for Utah to continue to build on its tremendous growth trajectory is to accept an invitation to join the Big 12 conference."

This media rights situation has shrunk the Pac-12 down to a total of four schools: Cal, Oregon State, Stanford and Washington State. Needless to say, the league's future is in peril.

"Today's news is incredibly disappointing for student-athletes, fans, alumni and staff of the Pac-12 who cherish the over 100-year history, tradition and rivalries of the Conference of Champions," the Pac-12 said in a Friday night statement. "We remain focused on securing the best possible future for each of our member universities."

Sources told Yahoo Sports' Ross Dellenger that leaders from the remaining four Pac-12 schools have discussed a potential merger or partnership with the Mountain West. The Mountain West has a $34 million exit fee to leave ahead of the 2024 season, so reforming the Pac-12 with expansion candidates from the MWC is an unlikely proposition, but a partnership of some sort could be a viable option.