  We consider the master fields for HS multiplets defined on 10-dimensional
tensorial extension \tilde{\cal M} of D=4 space-time described as a coset
\tilde{\cal M}={\cal M}/Sl(2;C) of 16-parameter Maxwell group {\cal M}. The
tensorial coordinates provide a geometrization of the coupling to constant
uniform EM fields. We describe the spinorial model in extended space-time
\tilde{\cal M} and by its first quantization we obtain new infinite HS-Maxwell
multiplets with their massless components coupled to each other through
constant EM background. We conclude our report by observing that
three-dimensional spinorial model with a pair of spinors should provide after
quantization D=3 massive HS-Maxwell multiplets.
