Complex sentence: At the same time AAT had commenced operations in the Northern Territory with five new Dennings, and in 1980 the two companies merged with the tours were marketed as Bill King's Australian Adventure Tours.
Split into simpler sentences: At the same time AAT Coachlines had commenced operations in the Northern Territory with five new Dennings. In 1980 AAT purchased King's business with the tours were marketed as Bill King's Australian Adventure Tours.