Complex sentence: Mohamed Mansour was born into one of the most prominent business families in Alexandria: the Mansour Group controls nine of Egypt's top Fortune 500 companies, though it needed to survive the nationalization and confiscation of its assets in 1965.
Split into simpler sentences: Mohamed Mansour was born into one of the most prominent business families in Alexandria. The family business, Mansour Group, controls nine of Egypt's top Fortune 500 companies, though it needed to survive the nationalization and confiscation of its assets in 1965.