  We study moduli stabilization in the context of M-theory on compact manifolds
with G2 holonomy, using superpotentials from flux and membrane instantons, and
recent results for the Khaeler potential of such models. The existence of
minima with negative cosmological constant, stabilizing all moduli, is
established. While most of these minima preserve supersymmetry, we also find
examples with broken supersymmetry. Supersymmetric vacua with vanishing
cosmological constant can also be obtained after a suitable tuning of
parameters.
