This paper presents a new decentralized internal model control (IMC) design method for controlling the multi-input multi-output plants that are subject to multiple operating regimes. Under this situation, the existing decentralized IMC design methods may become inadequate and conservative to be used for the resulting control problem mainly because they are developed based on a single model. To reduce the inherent conservatism in the existing design methods, a global multiple-model that accurately describes the plant in the operating space is incorporated into the proposed decentralized IMC design method. Simulation results illustrate that the proposed method is indeed less conservative than its conventional counterpart in controlling a plant with a range of operating points.