We have investigated a new electric field effect on magnetotransport in the multilayer systems where each layer is highly anisotropic. Under tilted magnetic fields, the resonant increase of interlayer conduction occurs when open electron orbits become periodic in k-space. The interlayer electric fields tilt the open orbits on two sheetlike Fermi surfaces in the different way, causing the split of the resonance. Using an organic conductor alpha-(BEDT-TTF)(2)KHg(SCN)(4), we have successfully proved the above scenario experimentally. (C) 2003 Published by Elsevier B.V.