For those on the FAA side of the pasture...
No requirement for Radar Altimeter in the certification of Transport Rotorcraft (according to 14 CFR 29).
It is installed in the S-92 (my current airframe), but is not required for dispatch according to the Master Minimum Equipment List (MMEL).
14 CFR 91.205 (h) does list a requirement for a radar altimeter for NVG operations.
Happy flying!