  We investigate the effect of the Continuous Spontaneous Localization (CSL)
model on light-pulse atom interferometry. Using a path-integral approach with
an additional stochastic potential accounting for CSL, we derive an exponential
loss of the contrast that scales linearly with the interferometer time $T$ if
both interferometer arms are spatially separated. We compare our theoretical
results with measurements from a cold rubidium atom interferometer based on
counter-propagating two-photon transitions with pulse separation times up to
$T$ = 260 ms and obtain the corresponding bounds on the CSL parameters.
