Utilizing the polyol process to produce ternary or multinary phases is a challenge due to the different redox potentials of the components. We succeeded in synthesizing compounds in the composition range Ni_4−δ(Sb_xTe_1−x)₆ (−0.20≤δ≤0.36, 0.13≤x≤0.3) by heating a basic ethylene glycol solution containing nickel(II) acetate, antimony(III) acetate, and ammonium tellurate(VI) in a microwave at 280 °C for 25 min without adding auxiliary reducing agents. The products consist of thin nano-platelets, which can be transformed into larger crystals by annealing. Single crystal X-ray diffraction revealed a new structure type for the composition Ni_4−δ(Sb_0.25Te_0.75)₆ (x=0.25) in the space group P (Formula presented.) m1 with a=3.897(1) Å and c=15.701(1) Å. The triple superstructure of the NiAs type is due to a complex concentration profile of the Ni atoms in the octahedral voids. The trigonal TlCdS₂ type is found for lower Sb contents (0≤x≤0.20), while for higher Sb contents (x≥0.28) the hexagonal Ni₂SbTe₂ type is adopted, which both are ordering variants of the NiAs type. Ni_4−δ(Sb_0.25Te_0.75)₆ is paramagnetic and exhibits poor metallic conductivity in the temperature range 6 K≤T≤300 K.