A method of correlating ternary liquid-liquid equilibrium data based on the model presented by Rod (1976, Chem. Engng J. 11, 105-110) is discussed and compared with other methods available in the literature. Several variants of the method are defined and corresponding computation algorithms are described. Their properties are tested on equilibrium data for the system isobutyl acetate-acetic acid-water at 25 degrees C presented by Heyberger et al. (1977, Collection Czech. Chem. Commun. 42, 3355-3362). The accuracy of the individual variants and the stability of the respective algorithms are demonstrated. A procedure for stabilizing the optimization and finding a unique solution is developed. The present correlation procedure compares favourably with other published methods.