  We calculate the magnetic field generated during bubble collisions in a
first-order electroweak phase transition that may occur for some choices of
parameters in the minimal supersymmetric Standard Model. We show that for
sufficiently gentle collisions, where the Higgs field is relatively unperturbed
in the bubble overlap region, the equations of motion can be linearized so that
in the absence of fermions the charged W fields are the source of the
electromagnetic current for generating the seed fields. Solutions of the
equations of motion for the charged gauge fields and Maxwell's equations for
the magnetic field in O(1,2) space-time symmetry are expressed in closed form
by applying boundary conditions at the time of collision. Our results indicate
that the magnetic fields generated by charged $W^{\pm}$ fields in the collision
are comparable to those found in previous work. The magnetic fields so produced
could seed galactic and extra-galactic magnetic fields observed today.
