  We report the application of the density-matrix renormalization group method
to a spatially anisotropic two-dimensional Hubbard model at half-filling. We
find a deconfinement transition induced by the transverse hopping parameter
$t_y$ from an insulator to a metal. Therefore, if $t_y$ is fixed in the
metallic phase, increasing the interaction $U$ leads to a metal-to-insulator
transition at a finite critical $U$. This is in contrast to the weak-coupling
Hartree-Fock theory which predicts a nesting induced antiferromagnetic
insulator for any $U>0$.
