Particle simulations are used to investigate plasma sheet convection in a realistic near-Earth magnetic field model including dipolelike and taillike regions. Convection leads to the formation of a thin current region characterized by a strong electrostatic potential and a depressed equatorial magnetic field component in which the cross tail current is carried predominantly by the electrons as a result of their E¿B and diamagnetic drifts. Implications for the thin current sheets observed in the near-Earth magnetotail during substorm growth phase are discussed. ¿ American Geophysical Union 1994