Abstract:
We prove that every group with nilpotent commutant, having an abelian normal subgroup such that the factor by this subgroup is nilpotent, is preorderable if and only if the group is $\Gamma$-torsion-free. An example is exhibited of a nonorderable $\Gamma$-torsion-free group with two-step nilpotent radical. This example demonstrates that for the variety of groups with nilpotent commutant the absence of $\Gamma$-torsion in a group is not a sufficient condition for orderability.