Precision Tests of the Mssm. *

We present the results of a global fit to the electroweak observables in the MSSM in which, for the first time, all the (relevant) low energy parameters of the model are treated as independent variables. The best fit selects either very low or very large values of tanβ and chargino (higgsino–like) and stop or/and the CP−odd Higgs boson are within the reach of LEP 2. Moreover, the best fit gives αs(MZ) = 0.114± 0.007, which is lower than the one obtained from the SM fits. The overall description of the electroweak data is better than in the SM. Those results follow mainly from the fact that in the MSSM one can increase the value of Rb ≡ ΓZ0→b̄b/ΓZ0→hadrons without modyfying the SM predictions for other observables. Supported in part by the Polish Committee for Scientific Research and European Union Under contract CHRX-CT92-0004. On leave of absence from Institute of Theoretical Physics, Warsaw University