The Pac-12 decided it won't expand further late Tuesday because commissioner Larry Scott failed to get assurance that Texas would back an equal revenue sharing plan if the league added the Longhorns, Oklahoma, Texas Tech and Oklahoma State, a source with direct knowledge told ESPN.com.

Scott didn't endorse expansion to the league's presidents and chancellors, the source said.

The presidents never took a vote on the four Big 12 schools and the four schools didn't formally apply for inclusion either, the source said. The Pac-12 member presidents were on a conference call Tuesday night and reaffirmed the decision to stay at 12 members.

"After careful review we have determined that it is in the best

interests of our member institutions, student-athletes and fans to

remain a 12-team conference," Scott said in a statement. "While we have great

respect for all of the institutions that have contacted us, and

certain expansion proposals were financially attractive, we have a

strong conference structure and culture of equality that we are

committed to preserve."

Texas, Oklahoma, Oklahoma State and Texas Tech were considering

a potential move from the Big 12 to the Pac-12. After expanding

from the Pac-10 with new members Utah and Colorado last year,

members of the new Pac-12 decided not to stretch the league farther

east.

"We were not surprised by the Pac 12's decision to not expand

at this time," Oklahoma President David Boren said. "Even though

we had decided not to apply for membership this year, we have

developed a positive relationship with the leadership of the

conference and we have kept them informed of the progress we've

been making to gain agreement from the Big 12 for changes which

will make the conference more stable in the future.

"Conference stability has been our first goal and we look

forward to achieving that goal through continued membership in the

Big 12 Conference."