This paper addresses the problem of partial state feedback compensation for large scale discrete systems. The eigenvalues of the closed-loop matrix should lie within a designated region of the z-domain to satisfy both stability and damping requirements. The system is to be compensated in such a way that only the eigenvalues that lie outside the desired region are affected. This is achieved through the use of the fast matrix sector function to decompose the system without solving for the eigenvalues. The decomposed system is then controlled using LQR design techniques. © 2010 AACC.