All GE through Harris upper tier radios since the M-RK (and Orion) feature this function. (M-RK, LPE, J700p, P7100, P7200, etc.)
The radios will generate a single alert tone, or even a two-tone sequence to trigger pagers.
BTW:
All of these radios will also DECODE single or two-tone paging signals.
I have my all of vhf radios programmed to decode the 1050 Hz alert tone issued by the NWS during severe weather. This way, I can keep updated on adverse weather warnings, but not have to listen their broadcast unless an actual alert is issued.