By using DFT calculations we show that nano-wires consisting of endohedral MSi12 cage-like molecules are stable especially for light transition metal elements (M = Fe, Ni, Co, Ti, V, and Cu). The nano-wire assemblies are stabilized by the metal atoms located along their principal axes and can be seen as close Si-based analogues of C nanotubes, but with hexagonal cross-section due to the D-6h-symmetry of their MSi12 building blocks. Independently on M, with the increase in the length of a (MSi12) m nano-wire, its HOMO-LUMO gap decreases gradually. The metallic behavior of (MSi12) m defines them as possible conductive components for self-assembled nano-devices. (C) 2008 Elsevier B.V. All rights reserved.