The partially mobile, plane-film model developed to describe film drainage and rupture during coalescence in liquid-liquid dispersions is extended to take account of interfacial-tension gradients generated by mass transfer. The resulting Marangoni forces are predicted to greatly accelerate film drainage (which in general corresponds to dispersed to continuous phase transfer) and to diminish film drainage in the negative case. The first model is based on the approximation of constant pressure and interfacial tensions outside the film. The predictions from this model agrees with observations and available numerical data, in the case of mass transfer from dispersed to continuous phase. While for mass transfer from continuous to dispersed phase, a second model is proposed, in this case the first model is adapted to take account of the location of the region of maximum concentration gradients, which moves radially outwards as a result of the growth of the continuous phase-concentration boundary layers. At large times, the new model predicts an asymptotic return to the drainage rate in the absence of mass transfer.