Complex sentence: If a unit owner chooses, he or she may join the "rental program", placing their units into the hotel's room inventory to be offered as luxury suites by The Signature when they are not occupied by the owner.
Split into simpler sentences: If a unit owner chooses, he or she may join the "rental program". This places their units into the hotel's room inventory to be used as luxury suites by The Signature when they are not occupied by the owner.