Foreword In recent years, the realization of cross-business synergies grew into a major concern of corporate management. Asked about their most pressing issues on the corporate agenda, managers from diff- ent multi-business firms in industries such as telecommunications, engineering, el- tronics, finance, energy, and automotive, mentioned the realization of cross-business synergies. Nevertheless, ever since Igor Ansoff introduced cross-business synergies into the field in the 1960s, research in strategy and organization has largely neglected their direct investigation. The questions of what cross-business synergies actually are and how they are realized remain largely unexplored. With this dissertation, the author aims at closing this gap in two steps. As the concept of synergy in the multi-business firm remains underspecified, he first develops a t- ory-based typology of cross-business synergies. In particular, the author conceptu- izes two new types of cross-business synergies, which contrast with the dominant ef- ciency-focused view of synergy in the multi-business firm (economies of scope): Growth synergies (profitable growth advantages from recombining complementary operative resources across businesses) and corporate management synergies (perfo- ance advantages from leveraging corporate management capabilities across bu- nesses). The concept of corporate management synergies is illustrated by a comp- hensive case study of General Electric.