In the present paper, we first establish a general theorem that gives the image of a modified H-transform in the fractional integral operator involving the multivariable H-function. Next, we deduce two important corollaries involving Wright generalized Bessel function, Mittag-Leffler function, Appell function F1 and the product of Whittaker functions which are also quite general in nature and of interest by themselves. Several other new and known results can also be obtained from our main theorem. We record here exact reference to one such known result.