Liquid-liquid equilibrium (LLE) data for three ternary systems consisting of {n-heptane or n-hexane or cyclohexane (I) + toluene (2) + gamma-butyrolactone (3)} were measured at 298.2 K and atmospheric pressure. The reliability of the experimental tie-line data was verified by using the Othmer-Tobias correlation. Distribution coefficients, separation factors and selectivity were evaluated for the immiscibility region. The experimental tie-line data were correlated by the UNIQUAC equation and also predicted with the UNIFAC model. The calculated results were compared with the experimental data. Better agreement with the experimental data was obtained by the UNIQUAC equation. The UNIFAC model does not provide reasonable correlations. (C) 2009 Elsevier B.V. All rights reserved.