  The light-trajectory in the gravitational field of N extended bodies in
arbitrary motion is determined in the first post-Newtonian approximation.
According to the theory of reference systems, the gravitational fields of these
massive bodies are expressed in terms of their intrinsic multipoles, allowing
for arbitrary shape and inner structure of these bodies. The results of this
investigation aim towards a consistent general-relativistic theory of light
propagation in the Solar system for high-precision astrometry at
sub-micro-arcsecond level of accuracy.
