  The results on the measurements of the top-quark mass, based on the data
collected by the Tevatron experiments CDF and D{\O}at Fermilab during {\RunI}
from 1992 to 1996 and {\RunII} since 2001, are summarized. The combination of
the published {\RunI} and preliminary {\RunII} results, taking correlated
uncertainties properly into account, is presented. The resulting preliminary
world average for the mass of the top quark is: $\MT=172.7\pm 2.9 \GeVc2$,
where the total error consists of a statistical part of $1.7 \GeVc2$ and a
systematic part of $2.4 \GeVc2$. Compared to the combination prepared for the
LP 2005 conference, this combination for the EPS-HEP 2005 conference includes
additional published {\RunI} and preliminary {\RunII} measurements.
