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We have used XMM-Newton's Optical Monitor (OM) images to study the localenvironment of a sample of 27 Ultraluminous X-ray Sources (ULXs) in nearbygalaxies. UVW1 fluxes were extracted from 100 pc regions centered on the ULXpositions. We find that at least 4 ULXs (out of 10 published) have spectraltypes that are consistent with previous literature values. In addition thecolors are similar to those of young stars. For the highest-luminosity ULXs,the UVW1 fluxes may have an important contribution from the accretion disk. Wefind that the majority of ULXs are associated with recent star-formation. Manyof the ULXs in our sample are located inside young OB associations orstar-forming regions (SFRs). Based on their colors, we estimated ages andmasses for star-forming regions located within 1 kpc from the ULXs in oursample. The resolution of the OM was insufficient to detect young densesuper-clusters, but some of these star-forming regions are massive enough tocontain such clusters. Only three ULXs have no associated SFRs younger than 50Myr. The age and mass estimates for clusters were used to test runawayscenarios. The data are in general compatible with stellar-mass binariesaccreting at super-Eddington rates and ejected by natal kicks. We also testedthe hypothesis that ULXs are sub-Eddington accreting IMBHs ejected bythree-body interactions, however this is not supported well by the data.

The Local Environment of Ultraluminous X-ray Sources Viewed by XMM Newton's Optical Monitor