  We report on a search for the supersymmetric partner of the top quark (stop)
produced in $t \bar{t}$ events using $110 {\rm pb}^{-1}$ of $p \bar{p}$
collisions at $\sqrt{s} = 1.8 {\rm TeV}$ recorded with the Collider Detector at
Fermilab. In the case of a light stop squark, the decay of the top quark into
stop plus the lightest supersymmetric particle (LSP) could have a significant
branching ratio. The observed events are consistent with Standard Model $t
\bar{t}$ production and decay. Hence, we set limits on the branching ratio of
the top quark decaying into stop plus LSP, excluding branching ratios above 45%
for a LSP mass up to 40 {\rm GeV/c}$^{2}$.
