Complex sentence: It is owned by the Irving, TX based Nexstar Broadcasting Group; through a Local Sales Agreement KLST and its parent company Nexstar Broadcasting operate KSAN-TV, the NBC affiliate in San Angelo which is owned by Mission Broadcasting.
Split into simpler sentences: It is owned by the Irving, TX based Nexstar Broadcasting Group. Through a Local Sales Agreement KLST and its parent company Nexstar Broadcasting operate KSAN-TV, the NBC affiliate in San Angelo which is owned by Mission Broadcasting.