  We have calculated a grid of massive star wind models and mass-loss rates for
a wide range of metal abundances between 1/100 and 10 Z/Zsun.
  The calculation of this grid completes the Vink et al. (2000) mass-loss
recipe with an additional parameter Z. We have found that the exponent of the
power law dependence of mass loss vs. metallicity is constant in the range
between 1/30 and 3 Z/Zsun. The mass-loss rate scales as Mdot \propto Z^0.85
Vinf^p with p = -1.23 for stars with Teff \ga 25000 K, and p = -1.60 for the B
supergiants with Teff \la 25000 K. Taking also into account the metallicity
dependence of Vinf, using the power law dependence Vinf \propto Z^0.13 from
Leitherer et al. (1992), the overall result of mass loss as a function of
metallicity can be represented by Mdot \propto Z^0.69 for stars with Teff \ga
25000 K, and Mdot \propto Z^0.64 for B supergiants with Teff \la 25000 K.
  Our mass-loss predictions are successful in explaining the observed mass-loss
rates for Galactic and Small Magellanic Cloud O-type stars, as well as in
predicting the observed Galactic bi-stability jump. Hence, we believe that our
predictions are reliable and suggest that our mass-loss recipe be used in
future evolutionary calculations of massive stars at different metal abundance.
A computer routine to calculate mass loss is publicly available.
