  We investigate the influence of a strong interior magnetic field on the
structure and composition of a protoneutron star allowing quark-hadron phase
transition. In contrast to protoneutron stars with noninteracting quark phase,
the stars with interacting quark phase have smaller maximum star masses than
those of neutrino-free stars. The strong field makes the overall equation of
state softer compared to the field-free case favoring the evolution of a
protoneutron star more towards a neutron star than a black hole.
