A true domain decomposition method to obtain numerical solution involving electrically large bodies using the method of moments (MOM) formulation is the subject matter of the present work. The electrically large body is initially divided into smaller sub-structures. By defining a set of new basis functions adaptively, utilizing the primary basis functions, a solution scheme is developed which completely eliminates the interaction of one substructure with the rest of the body. This procedure enables to solve each substructure independently and involves no iterative solution as a final step. The present method is conceptually simple and applicable to any MOM solution. Further, the method can easily handle multiple right-hand side vectors much the same way as the conventional MOM solution. A few representative numerical examples are presented to illustrate the applicability of the new method.