  The evolution of the magnetic helicity tensor for a nonzero mean magnetic
field and for large magnetic Reynolds numbers in an anisotropic turbulence is
studied. It is shown that the isotropic and anisotropic parts of the magnetic
helicity tensor have different characteristic times of evolution. The time of
variation of the isotropic part of the magnetic helicity tensor is much larger
than the correlation time of the turbulent velocity field. The anisotropic part
of the magnetic helicity tensor changes for the correlation time of the
turbulent velocity field. The mean turbulent flux of the magnetic helicity is
calculated as well. It is shown that even a small anisotropy of turbulence
strongly modifies the flux of the magnetic helicity. It is demonstrated that
the tensor of the magnetic part of the alpha-effect for weakly inhomogeneous
turbulence is determined only by the isotropic part of the magnetic helicity
tensor. Astrophysical applications of the obtained results are discussed.
