In order to transmit or store three-dimensional (3-D) mesh models efficiently, we need to simplify them. Although the quadric error metric (QEM) provides fast and accurate geometric simplification of 3-D mesh models, it cannot capture discontinuities faithfully. Recently, an enhanced QEM based on subdivided edge classification has been proposed to handle this problem. Although it can capture discontinuities well, it has slight degradation in the reconstruction quality. In this paper, we propose a novel mesh simplification algorithm where we employ a normal variation error metric, instead of QEM, to resolve the quality degradation issue. We also modify the subdivided edge classification algorithm to be cooperative with the normal variation error metric while preserving discontinuities. We have tested the proposed algorithm with various 3-D VRML models. Simulation results demonstrate that the proposed algorithm provides good approximations while maintaining discontinuities well.