In this paper we study the cross-functional integration of project sales and project operations—two crucial functions when conducting business in global project-based firms. In particular we address contextual factors that are associated with integration needs among project sales and operations functions across project phases and report on how integration is managed across phases in three global projects with different contextual conditions. Using Galbraith's (1973) and Tushman and Nadler's (1978) model of the organization as an information processing system as our theoretical lens, we develop a set of propositions drawn from the general arguments of the theory and illustrated by these observations. The proposed theory underlying these propositions begins to explain how the contextual variables drive the use of different cross-functional integration mechanisms for sales and operations across project phases in global project-based firms. Subsequent research focusing on these and other key functions that require integration in different project phases can begin to validate and further elaborate this contingent framework for cross-functional integration in global project-based firms