  We present a computation of QCD next-to-leading order virtual corrections to
the top production and decay process at linear colliders. The top quarks are
allowed to be off-shell and the production and decay subprocesses are treated
together, thus allowing for interference effects. The framework employed for
our computation is the double pole approximation (DPA). We describe the
implementation of this approximation for the top production and decay process
and compare it with the implementation of DPA for the evaluation of QED
corrections to the W pair production at LEP II. Similarities and differences
between the two cases are pointed out. One result of interest is the incomplete
cancelation of interference corrections. Other results include values for the
total NLO top production cross section, and the impact the nonfactorizable
(interference) corrections have on the top invariant mass distribution.
