  Analytical solutions are constructed for an assembly of any finite number of
bubbles in steady motion in a Hele-Shaw channel. The solutions are given in the
form of a conformal mapping from a bounded multiply connected circular domain
to the flow region exterior to the bubbles. The mapping is written as the sum
of two analytic functions---corresponding to the complex potentials in the
laboratory and co-moving frames---that map the circular domain onto respective
degenerate polygonal domains. These functions are obtained using the
generalised Schwarz-Christoffel formula for multiply connected domains in terms
of the Schottky-Klein prime function. Our solutions are very general in that no
symmetry assumption concerning the geometrical disposition of the bubbles is
made. Several examples for various bubble configurations are discussed.
