  The frustrated spin-1/2 model with weakly anisotropic ferromagnetic
nearest-neighbor and antiferromagnetic next-nearest-neighbor exchanges is
studied with use of variational mean-field approach, scaling estimates of the
infrared divergencies in the perturbation theory and finite-size calculations.
The ground state phase diagram of this model contains three phases: the
ferromagnetic phase, the commensurate spin-liquid phase and the incommensurate
phase. The non-trivial behavior of the boundaries between these phases and the
character of the phase transitions in case of weak anisotropy are determined.
