Complex sentence: Trained as a lawyer, he early diversified the Chicago-based family business, the Marmon Group, into lumber, and with his engineer brother, Robert Pritzker (1926 --), he built a portfolio of 60 diversified industrial corporations.
Split into simpler sentences: Trained as a lawyer, he early diversified the Chicago-based family business, the Marmon Group, into lumber. With his brother Robert Pritzker, he built a portfolio of 60 diversified industrial corporations.