An approximate analytical solution of the problem of the spectrum of plasma oscillations in a system of two metallic nanospheres is presented. The essence of the approximation is that the field of each sphere is replaced by the field of a dipole with a finite arm, the center of the dipole being shifted from the sphere center. The magnitudes of the shift and the armare determined from the boundary conditions for the electric field in quasistatic approximation. The results are in good agreement with previous results of other studies. The proposed method has several advantages compared with numerical methods and other approximate analytical methods.