  We consider the process of top-antitop production from electron-positron
annihilation, for c. m. energies in the few TeV regime, in the MSSM theoretical
framework. We show that, at the one loop level, the \underline{slopes} of a
number of observable quantities in an energy region around 3 TeV are only
dependent on $\tan\beta$. Under optimal experimental conditions, a combined
measurement of slopes might identify $\tan\beta$ values in a range $\tan\beta<
2$, $\tan\beta>20$ with acceptable precision.
