  New nonlinear equations for field correlators in the large $N_c$ gluodynamics
are derived. Nonperturbative confining correlators are shown to satisfy a
system of nonlinear scale-invariant equations. Keeping only the simplest,
bilocal correlators one can find the exponential large distance behaviour for
both independent correlators $D$ and $D_1$ and express coefficients in the
exponentials -- the gluonic correlation length $T_g$ -- through the string
tension. Numerically these results are in agreement with lattice data.
