Formation and Migration of Trans-Neptunian Objects
  We suppose that some large trans-Neptunian objects could be formed directly by the compression of rarefied dust condensations of the protoplanetary disk, but not by the accretion of smaller planetesimals. About 0.0015 of former Jupiter-crossing objects can get orbits with aphelia inside Jupiter's orbit (mainly less than 4.7 AU) during more than 1 Myr. A considerable portion of near-Earth objects could have come from the trans-Neptunian belt. 
S.I. Ipatov