Complex sentence: Stigwood liked the title "Night Fever" but was unsure of marketing a movie with that name, so he combined the two suggestions and the idea for "Saturday Night Fever" as a motion picture was born.
Split into simpler sentences: Stigwood liked the title "Night Fever" but was wary of marketing a movie with that name. He combined the two suggestions and the idea for "Saturday Night Fever" as a motion picture was born.