  We investigate transport of correlated fermions through a junction of three
one-dimensional quantum wires pierced by a magnetic flux. We determine the flow
of the conductance as a function of a low-energy cutoff in the entire parameter
space. For attractive interactions and generic flux the fixed point with
maximal asymmetry of the conductance is the stable one, as conjectured
recently. For repulsive interactions and arbitrary flux we find a line of
stable fixed points with vanishing conductance as well as stable fixed points
with symmetric conductance (4/9)(e^2/h).
