The Pac-10 announced Thursday that the University of Colorado has agreed to leave the Big 12 to join its conference.
Nebraska is also poised to announce its move from the conference to the Big Ten.
Texas and Texas A&M officials were to meet Thursday at an undisclosed location to discuss the future of their athletic programs and the Big 12 amid speculation the league could be raided by rival conferences and broken apart.
Texas athletic director DeLoss Dodds has said he wants to keep the Big 12 together.
Baylor and Texas Tech officials have said that even if the Big 12 breaks apart, they want to remain with Texas and Texas A&M as members of the same conference.
A Big 12 football coach, who spoke on the condition of anonymity, told ESPN.com's Mark Schlabach on Wednesday night that if Nebraska left the Big 12 the conference would dissolve, according to his athletics director and university president. The coach said Texas, Texas A&M, Texas Tech, Oklahoma, Oklahoma State and Colorado would join the Pac-10, leaving Baylor, Kansas, Kansas State, Missouri and Iowa State behind.
The coach said the Pac-10 favored Colorado over Baylor because of the Buffaloes' presence in the Denver TV market.
"Nebraska is the key," the coach said.
A source close to the Nebraska program told ESPN's Chris Mortensen that athletic director Tom Osborne informed some staff members within the past 24 hours the Cornhuskers were going to make the move to the Big Ten.
A source with knowledge of the Big Ten's plans confirmed to ESPN.com's Adam Rittenberg that Nebraska will join the Big Ten by the end of this week or early next week. The source said the formal process of accepting a candidate either has started or would be under way shortly, as Nebraska must formally apply for admission to the Big Ten.
"It's going to happen, unless something crazy happens in the final hours," the source said. "I think by this weekend, it's going to be wrapped up."
Besides Nebraska, no other candidates are imminent for the Big Ten, which could stay put with 12 members, the source said.