In this work, we studied the local environment of a series of LiNiyMnyCo1-2yO2 materials synthesized by wet chemistry via oxalate route. Measurements included the temperature dependence of the magnetic susceptibility chi(m)(T), the magnetization M(H), and the electron spin resonance. The influence of the synthesis conditions on the magnetic and electronic properties is presented and discussed. Magnetic properties and electron spin resonance spectroscopy provides further information on Ni2+, Mn4+ ion distribution in LiNiyMnyCo1-2yO2. The magnetic data allows the determination of the cationic disorder, i.e. the concentration of Ni2+ ions in the 3a lithium sites, as a function of the composition, in quantitative agreement with the results of XRD experiments. We find that the lithium extraction proceeds by different steps. In a first step, Ni2+ in converted first in Ni3+, then in Ni4+ as x decreases from x = 1, while Co remains in the Co3+ valence state. The ESR spectra show a resonance due to Mn4+, which is analyzed self-consistently with magnetic experiments. (C) 2011 Elsevier B. V. All rights reserved.