  RX J1211+2242 is an optically faint (B = 19.2 mag) but X-ray bright (2 - 10
keV flux fx = 5e-12 erg/cm**2/sec) AGN, which has been shown to be a BL Lac
object at redshift z = 0.455. The ROSAT X-ray, Calar Alto optical, and NVSS
radio data suggest that the peak of the synchrotron emission of this object is
at energies as high as several keV. BeppoSAX observations have been carried out
simultaneously with optical observations in order to extend the coverage to
higher energies. The new data indeed indicate a turn-over in the 2 - 10 keV
energy region. We propose that RX J1211+2242 is the counterpart of the
unidentified EGRET source 3EG J1212+2304, making it a gamma-ray emitter with
properties similar to, for example, Markarian 501 in its bright state, though
being at a much larger distance.
