To secure good deals, an agent may engage in multiple concurrent negotiations for a particular good or service. However for this to be effective, the agent needs to carefully coordinate its negotiations. At a basic level, such coordination should ensure the agent does not procure more of the good than is needed. But to really derive benefit from such an approach, the agent needs the concurrent encounters to mutually influence one another (e.g. a good price with one opponent should enable an agent to negotiate more strongly in the other interactions). To this end, this paper presents a novel heuristic model for coordinating multiple bilateral negotiations. The model is empirically evaluated and shown to be effective and robust in a range of negotiation scenarios.