Complex sentence: From 1960 to 1968 he was the newspaper's correspondent in London, returning to Montreal to eventually become an Associate Editor of the "Star" before his increasing disenchantment with corporate media caused him to resign and become a freelancer in 1971.
Split into simpler sentences: From 1960 to 1968 he was the newspaper's correspondent in London. He returned to Montreal eventually becoming an Associate Editor of the "Star" before his increasing disenchantment with corporate media caused him to resign and become a freelancer in 1971.