We have proposed a statistical-mechanical theory of a nematic liquid crystal composed of ellipsoidal molecules interacting through angle-dependent nonseparable potentials in contact with a solid interacting surface. The theory takes into account pair intermolecular correlations. Within the framework of the theory the concept of an average force potential is used to develop a truncation procedure for arbitrary equation of the chain. The closed system of integral equations for average force potential is similar to that used by Brook-Levinson and Zakharov for uniform nematic phase. These equations are solved numerically and results are given for the cubic closed packing ellipsoidal molecules interacting through Berne-Pechukas potentials. Although the calculations have been made for the nematic liquid crystal, the general approach can be applied to any liquid crystalline phase.