This paper presents a Model Predictive Control (MPC) formulation with constraint aggregation using the Kreisselmeier-Steinhauser (KS) function. The KS aggregation function provides an approximation of the feasible region with a reduced number of nonlinear constraints. The application to linear MPC is considered and the implementation aspects are discussed. Case studies including an application to very flexible aircraft are presented. Numerical results show that a significant reduction in computation time can be achieved.