  We performed a systematic search for stellar tidal disruption events (TDE) by
looking for X-ray sources that were detected during the ROSAT All Sky Survey
and faded by more than an order of magnitude over the next two decades
according to XMM-Newton serendipitous observations. Besides a number of highly
variable persistent X-ray sources (like active galactic nuclei and cataclysmic
variables), we found three sources that are broadly consistent with the TDE
scenario: 1RXS J114727.1+494302, 1RXS J130547.2+641252, and 1RXS
J235424.5-102053. A TDE association is also acceptable for the fourth source,
1RXS J112312.7+012858, but an AGN origin cannot be ruled out either. This
statistics implies a TDE rate of $ \sim 3\times 10^{-5} $ yr$ ^{-1} $ per
galaxy in the Universe within $z\sim 0.18$, which is broadly consistent with
the estimates of the TDE rate in the more local Universe obtained previously.
