For an invertible H-matrix A, a classical result involving A −1 and its comparison matrix was proved by Ostrowski. More recently, these were improved by Neumaier and Kolotilina. In this article, we have endeavoured to generalize these inequalities for the group inverse of A, in the presence of certain conditions, involving a specific extension of a notion of diagonal dominance. A result of Fan for invertible M-matrices is also extended for H-matrices. © 2018 Elsevier Inc.