Expansion in Terms of Negative Powers



I'm using maxima for some Control Systems homework problems, and I'm
wondering if there's some way to do expansions in terms of negative
powers.  E.g., instead of
  (%i11) expand((0.5*(z^2-1.6*z+0.6))/z);
  (%o11) 0.5*z+0.3/z-0.8
I'd like to see
  (%o11') 0.5*z-0.8+0.3*z^-1
since that form, when formatted (0.5z - 0.8 + 0.3z??), is the
customary form of the expression in controls.

Is there such an option?

--Joel