[en] In the framework of the mSUGRA model which provides a simple breaking mechanism of supersymmetry, sparticles with masses beyond the kinematic reach of the LEP-II experiments may be produced at the Tevatron pp-bar collider at a center of mass energy of 1.96 TeV. A promising source of sparticles at the Tevatron collider is the associated production of the lightest chargino, χ-tilde₁^±, and the next to lightest neutralino, χ-tilde₂⁰. Leptonic decay modes, χ-tilde₂⁰ → χ-tilde₁⁰l⁺l^- and χ-tilde₁^±l^±ν_l, lead to a clean detector signature with three leptons and a large amount of missing transverse energy. In order to increase the sensitivity to signal in regions of mSUGRA parameters space leading to a very soft third lepton with small reconstruction efficiency, a selection based on 2 like sign leptons plus missing transverse energy has been developed. The particular signature with 2 like sign muons is presented in this work. No evidence for supersymmetry has been observed in a dataset collected from April 2002 to February 2006 with the D0 detector at the Tevatron collider and corresponding to an integrated luminosity of 0.9 fb^-1. Then, limits on the product of the cross-section and the 3-leptonic branching ratio, σ(pp-bar → χ-tilde₁^±χ-tilde₂⁰) * BR(3l), have been set as a function of the χ-tilde₁^± mass. The results obtained with the like sign dimuon selection have been combined with the results of three tri-lepton selections. For mSUGRA models with enhanced leptonic decays, a χ-tilde₁^± mass limit of 140 GeV/c² has been derived at 95% confidence level. (author)