The quark-gluon mixed condensate $g$ is calculated in the Gaussian approximation of the Field Correlator Method. In the large N_c limit and for zero mass quarks one obtains a simple result, $m^2_0 \equiv \frac{g}{} = \frac{16σ}π$, where $σ$ is the string tension. For a standard value $σ=0.18 GeV^2$ one obtains $m^2_0=1 GeV^2$ in good agreement with the QCD sum rules estimate $m^2_0 = (0.8\pm 0.2) GeV^2$ and the latest lattice result $m^2_0 \cong 1 GeV^2$.

10 pages, no figures; discussion of accuracy of the result added and misprints corrected