The stationary solutions of the wave equation describing gravitational perturbations in a curved background are considered. The curved background is a de–Sitter metric (including a cosmological term Λ). The metric perturbations are generated by a long line mass current. The solutions to the wave equation are linear in Λ and can be interpreted physically in comparison with the corresponding solutions in the flat background (Λ=0, i.e. familiar gravito-electromagnetic fields). Presence of the cosmological term weakens the gravito-electric field by an outward vector field as if it arisen from a negative charge mass distribution. Presence of the cosmological term strengthens the gravito-magnetic field by an azimuthal vector field as if it arisen from a variable linear volume current. From the dark energy point of view, a theoretical method is proposed to determine the sign of cosmological term in galactic or cosmic scales.
