This paper discusses a new type of wire media based on amorphous ferromagnetic microwires. The combination of two effects, namely, a strong dispersion of the effective permittivity in metallic wire composites (resonance or plasmonic type) and giant magnetoimpedance effect in wires will result in unusual property that an effective dielectric response may strongly depend on the wire magnetization which can be changed with different external stimuli. We have demonstrated the effect of the external magnetic field on microwave response from composites containing CoFeSiBCr amorphous wires in free space at microwave frequency.