An aerial service wire (20) includes a jacket (40) having a generally rectangularly shaped cross section and comprising a polyvinyl chloride plastic material. Enclosed by the jacket are two groups of strength members (36--36) each of which includes a plurality of filaments and each of which is impregnated with a material which is compatible with that of the jacket. The strength members are disposed along axes (52,54) of the cross section which are normal to an axis (42) which passes through a geometric center through which a longitudinal axis (50) of the jacket passes. Conductors (30--30) which are individually insulated are disposed adjacent to the longitudinal axis with each strength member being disposed between the conductors and the outer surface of the jacket.