  Motivated by the recent finding of superconductivity in layered CoO_2
compounds, we investigate superconducting and magnetic instabilities of
interacting electrons on the two-dimensional triangular lattice. Using a
one-loop renormalization group scheme for weak to moderate coupling strengths,
we find that for purely local interactions U>0 and small Fermi surfaces the
renormalization group flow remains bounded down to very low scales and no
superconducting or other instabilities can be detected. Antiferromagnetic
exchange interactions J generate a wide density region with a
d_{x^2-y^2}+id_{xy}-wave superconducting instability similar to recent
proposals for the strongly correlated t-J model. For larger Fermi surface
volumes the interactions flow to strong coupling also for purely local
interactions U>0. We find a singlet pairing instability in the vicinity of
strong magnetic ordering tendencies at three wavevectors for the van Hove
filling.
