  We investigate electron transport through a diatomic molecule parallelly
coupled to infinite source and drain contacts. We utilize a model Hamiltonian
involving a Hubbard term in which the contacts are modeled using recently
developed complex source and sink potentials. The zero bias transmission
spectrum for a symmetrically coupled system as a function of the Fermi energy
acquires a Fano lineshape as the Hubbard interaction is turned on. For large
values of $U$, the Fano lineshape broadens and shifts to higher energy values
disappearing eventually. Meanwhile, the Breit-Wigner resonance located at the
bonding resonance in the noninteracting limit survives but its position is
shifted twice the coupling between the atoms in the molecule in the infinite
$U$ limit and its linewidth is reduced to half. We attribute this behaviour to
the unavailability of one of the transmission channels due to Coulomb blockade.
