Alumina supports were synthesized from aluminum hydroxide produced by the hydrolysis of secondary aluminum butoxide in the presence of the triblock copolymer Pluronic P123 (m-AlOOH) and from the commercial AlOOH pseudoboehmite powder (TH-AIOOH), as well as by mixing of m-AlOOH and TH-AIOOH gel in a ratio of 5:95 (m-TH-AIOOH sample). NiW/Al2O3 catalysts were prepared by impregnation of the synthesized supports with H3PW12O40 heteropolyacid and nickel citrate. Physicochemical properties of the supports and catalysts were investigated by low-temperature nitrogen adsorption, X-ray diffraction, NH3 thermo-programmed desorption, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy. Catalytic properties were tested in hydrotreatment of straight-run gas oil and vacuum gasoil on a flow unit. The resulting hybrid support had a non-additively higher average pore radius (75 angstrom) and surface area (307 m(2)/g) than a conventional alumina support and hence preferred morphology of NiWS active phase (3.8 nm against 6.6 rim with the same stacking number) and an increase in the W sulfidation degree (68% against 54%) and Ni content in NiWS phase (44% against 26%). Therefore, the catalyst on the hybrid support exhibits higher activity in hydrodesulfurization, hydrodenitrogenation and hydrogenation of petroleum feeds, and a lower degree of deactivation and coke formation.