  The loss rate of linear momentum from a binary system composed of compact
objects (radially falling towards each other under mutual gravitational
influence) has been investigated using the multipolar post-Minkowskian
approach. The 2.5PN accurate analytical formula for the linear momentum flux is
provided, in terms of the separation of the two objects, in harmonic
coordinates, both for a finite and infinite initial separation. The 2.5PN
formulas for the linear momentum flux are finally used to estimate the recoil
velocity accumulated during a premerger phase of the binary evolution.
