Complex sentence: Originally, hotels branded as "Prince Hotels" were not wholly owned by Prince Hotels Company, but were instead operated by different companies, such as Seibu Railway, Kokudo, or Izuhakone Railway.
Split into simpler sentences: Originally, hotels branded as "Prince Hotels" were not wholly owned by Prince Hotels Company. Rather, they were operated by different companies, such as Seibu Railway, Kokudo, or Izuhakone Railway.