Partially decentralized control is a control structure that lies between a fully decentralized structure and a fullycentralized one, and has the advantage of achieving comparable performance as a fully centralized controller but with simplerstructure. This paper proposes an expansion procedure to design partially decentralized controllers via generalized predictivecontrol (GPC). The proposed method does not need to compute the pseudo-inverse of a non-square system thus overcomes thedrawbacks of the existing expansion method proposed in a previous paper. Simulation results show that the proposed method issimple and can achieve better performance than the previous method.