Complex sentence: Most of ESPN's syndicated broadcasts were presented under the on-air brand ESPN Plus, which was later phased out in favor of conference-specific brands for each package, such as "SEC TV" and the "Big 12 Network".
Split into simpler sentences: Most of ESPN's syndicated broadcasts had been presented under the on-air name ESPN Plus. However, the brand has since been phased out from its productions in favor of conference brands, such as "SEC TV" and the "Big 12 Network".