We investigate dissociation reactions of loosely bound and spatially extend
ed three-body systems. We formulate a practical method for simultaneous tre
atment of long-range Coulomb and short-range nuclear interactions. We use H
e-6 (n+n+alpha) and Li-11 (n+n+Li-9) as examples and study the two-neutron
separation cross-sections as functions of target and beam energy. Individua
l Coulomb and nuclear as well as interference contributions are also extrac
ted.