Isothermal vapour-liquid equilibrium data have been measured for the ternary system (di-isopropyl ether + isobutanol + benzene) and two of the binary systems involved (di-isopropyl ether + isobutanol) and (isobutanol + benzene) at 313.15 K. A static technique consisting of an isothermal total pressure cell was used for the measurements. Data reduction by Barker's method provides correlations for G(E) using the Margules equation for the binary systems and the Wohl expansion for the ternary system. Wilson, NRTL and UNIQUAC models have been applied successfully to both the binary and the ternary systems. (c) 2005 Elsevier B.V. All rights reserved.