  We analyse the measured critical current $I_{m\text{}}$ in a mesoscopic
4-terminal S/N/S structure. The current through the S/N interface is shown to
consist not only of the Josephson component $I_{c}\sin \phi ,$ but also a
phase-coherent part $I_{sg}\cos \phi $ of the subgap current. The current
$I_{m}$ is determined by the both components $I_{c}$ and $I_{sg},$ and depends
in a nonmonotonic way on the voltage $V$ between superconductors and normal
reservoirs reaching a maximum at $V\cong \Delta /e$. The obtained theoretical
resultas are in qualitative agreement with recent experimental data.
