Well, the FAA MASPS listing shows N12UM as operated by UTFLIGHT as monitored on 8/7/10, while the registration was transferred to TNT Aero on the 2/4/10, so it seems that the transfer was just some financial or legal manoeuvre. I've done it for UTFLIGHT anyway:
N12UM - GLF4 of UTFLIGHT (United Technologies Flight Department), who also operate N100U N310U N308U N12U N34U and N408U.
EDIT - rats! I see I've already done it for N34U!
Sorry - can't find anything useful for PH-ECI except a dead website for Ypsilon
Rod