Complex sentence: Although Gordon made huge profits on some promotions, others lost heavily and by 1960 he was deep in debt and sold Lee Gordon Records and the Leedon label to Festival Records against the advice of business manager Alan Heffernan.
Split into simpler sentences: Although Gordon made huge profits on some promotions, others lost heavily and by 1960 he was heavily in debt. He sold Lee Gordon Records and the Leedon label to Festival Records against the advice of business manager Alan Heffernan.