Exact solutions are given for the steady flow of a Newtonian fluid occupying the halfspace l S past the plane z=0 uniformly rotating about a fixed normal axis (z-axis) when a uniform magnetic field H_0 orthogonal to the plane is impressed. The plane is supposed electrically non conducting. The solutions are obtained in a velocity field of the form considered by Berker and supposing the induced magnetic field depending only on z. The results are compared with those corresponding to the Newtonian non electrically conducting case and can be deduced as a limiting case, as l goes to infinity, of the solution to the problem relative to the strip 0< z < l.