We have designed a system to support collaborative case reasoning and building in corporate litigation cases, that is, processes of bringing and pursuing lawsuits. The design was based on our understanding of the domain acquired through analysis of the literature, interviews of various parties involved in corporate litigation processes, and studies of the commercial tools already available. In this paper we illustrate the designed system and in particular the interaction modes that it support that we believe would address a number of the requirements that emerged through our analysis. We also describe the main components of the designed system and their integration, including a knowledge model used to represent the domain, and a natural language processing component for extracting semantic information. A description of the first prototype of the system is also provided.