Abstract: An overhead transmission line composed of a coaxial line element constituted by a central conductor and an insulating sheath concentrically surrounding the central conductor; and a plurality of power current conductors of circular cross section presenting electrically conductive surface portions and disposed around the coaxial element in such a manner that adjacent current conductors contact one another and the insulating sheath, the surface regions of the power conductors which face said sheath together defining a cage-like return conductor enclosing the central conductor.