  We study nonlinear resolvents of holomorphic generators of one-parameter
semigroups acting in the open unit disk. The class of nonlinear resolvents can
be studied in the framework of geometric function theory because it consists of
univalent functions.
  In this paper we establish distortion and covering results, find order of
starlikeness and of strong starlikeness of resolvents. This provides that any
resolvent admits quasiconformal extension to the complex plane $\C$. In
addition, we obtain some characteristics of semigroups generated by these
resolvents.
