In the 1970s, Schwartz worked at Bear Stearns. In 1976, his mentor Jerome Kohlberg, Jr. left, followed by Henry Kravis and George Roberts. The trio later founded Kohlberg Kravis Roberts. Schwartz left Bear Stearns shortly afterward and returned to Canada. Along with Izzy Asper, Schwartz co-founded CanWest Global Communications in 1977.