  We present results of tunneling studies of p-Hg_{1-x}Cd_{x}Te-oxide-Al
structures with 0.165<x<0.2 in a magnetic field up to 6 T. The tunneling
conductivity oscillations resulting from the Landau quantization of the energy
spectrum in the semiconductor volume are investigated. Under an in-plane
magnetic field the amplitudes of tunneling conductivity maxima connected with
the tunneling into `a' and `b' spin sublevels are found to differ
substantionally from one another, and the amplitude ratio varying from
structure to structure. To understand the cause of this behavior, the tunneling
conductivity for this magnetic field orientation is calculated taking into
consideration the multi-band energy spectrum. It is shown that the
contributions of the different spin-sublevels to the tunneling conductivity are
dissimilar and the relationship between them depends strongly on the value of
surface potential.
