abstract Business groups are the primary form of managing large business organizations outside North America. This paper provides a systematic and integrative framework for understanding business groups. We argue that existing theoretical perspectives of business groups pay attention to four critical external contexts, each of which draws from a specific theoretical perspective: market conditions (transaction cost theory), social relationships (relational perspective), political factors (political economy perspective), and external monitoring mechanisms (agency theory). Business groups adapt to these external forces by deploying various internal mechanisms along two key dimensions: one focuses on the distinctive roles of the group affiliates (horizontal connectedness) and the other focuses on coupling and order between the parent firm and its affiliates (vertical linkages). Based on these two dimensions, a typology of business group forms is developed: network (N-form), club (C-form), holding (H-form), and multidivisional (M-form). Utilizing this model we provide research questions which facilitate an improved future research agenda.