We report on the progress in work on improving precision of the standard model theoretical predictions for the top quark pair production and decay into six fermions at a linear collider. Two programs have been combined into a single Monte Carlo program:  eett6f, a MC program for e⁺e^- \to 6f, and  topfit, a program for electroweak radiative corrections to e⁺e^- \to t{\bar t}. The MC program is described and preliminary numerical results are shown.

PACS numbers: 12.15.--y, 13.40.Ks, 14.65.Ha