In this paper, we describe the specification of communication relationships between objects in a framework for object-oriented conceptual modeling of information systems. In our approach, objects have an observable state and can evolve by the occurrence of events. The possible behavior of objects over time is modeled by a set of admissible object life cycles. A high-level approach to specify systems of interacting objects should provide a means to specify communications between objects explicitly. We introduce language features for the specification of communications and present an approach to transform such relationships into communication channels in order to make implementation easier.