For a class of single-output processes with at least two control inputs, this note proposes a simple control design and study its stability. To this end, the process is factorized into a stable and non-minimum-phase factor and a possible unstable minimum-phase factor. By the addition of a (low-pass) filter of suitable dimension, one can obtain a process factorization where the minimum-phase factor has a proper and stable inverse. Once the plant has been factorized in this form, the proposed control synthesis method is composed of two main steps; namely, output regulation based on the non-minimum-phase factor and design of an optimization-based divider to compute the value corresponding to the multiple inputs. In this way, one obtains the control transfer function of each control input in a parallel control architecture. An analysis of the control structure is provided, giving sufficient conditions for the stability of the control loop. (C) 2004 Published by Elsevier Ltd.