The Big Ten Conference threw the world of big-time sports into a tizzy last December , when the 11-university league (long story) announced that it would consider adding new members, setting off widespread speculation about whether it would look East (to the University of Notre Dame or members of the Big East Conference) or West (to members of the Big 12 Conference) to expand. The Big Ten set an 18-month timetable for its deliberations, but the rival Pacific-10 Conference may have altered that schedule with its own statements in recent days  indicating that it is considering adding as many as six new members to become a mega-conference that, like the Southeastern and Big Ten Conferences, could have its own television network. Pac-10 officials said Sunday that league presidents had given permission to Commissioner Larry Scott to make decisions on expansion without consulting them further. The Pac-10 is said to be considering adding a group of institutions from the Big 12 (names mentioned include Texas, Texas A&M, Texas Tech, Baylor, Colorado, Oklahoma and Oklahoma State), defections that could decimate the Big 12 if members such as Missouri and Nebraska were to bolt for the Big Ten. News reports  over the weekend suggested (without confirmation from the colleges involved) that the Big 12 had given Nebraska and Missouri an ultimatum on deciding on their next moves. Big Ten presidents met Sunday but concluded their meeting without any announcements, the Detroit Free Press reported .