The document presents a new aggregation procedure for decentralized stabilization of large scale linear interconnected systems. The previous aggregation methods in the literature contained a major gap, as the interaction terms were incorrectly aggregated with the subsystem matrices. The new procedure proposed removes this gap by suggesting a different aggregation approach. It derives inequalities to bound and decouple the interaction terms between subsystems. This allows the subsystems to be stabilized independently through optimal control, ensuring stability of the overall system. The method is illustrated with a numerical example.