Methanol and electrolytes are often used to inhibit gas hydrate formation in industrial operations. In order to design such equipment it is required to compute the inhibition effects of these additives. Development of methods for calculating the inhibition effects require accurate experimental hydrate equilibria data. In the present work, experimental three phase (aqueous liquid solution, Vapor and incipient solid hydrate) equilibrium data for a ternary mixture of methane, propane and CO2 and a natural gas mixture in the presence of methanol and electrolytes were obtained. The experiments were carried out in the temperature range of 274-291 K and pressure range of 1.5-10.1 MPa. A 'full view' variable volume sapphire cell with a movable piston, described earlier by Dholabhai et al. [P.D. Dholabhai, J.S. Parent, P.R. Bishnoi, Equilibrium conditions for hydrate formation from binary mixtures of methane and carbon dioxide in the presence of electrolytes, methanol and ethylene glycol, Fluid Phase Equilibria 141 (1997) 235-246.], was used to gather the data.