  Among over 200,000 Galactic Bulge variable stars in the public domain OGLE
catalogue, we found over 15,000 red giant variables following two well defined
period -- amplitude relations. The periods are in the range 10 < P < 100 days,
and amplitudes in the range 0.005 < A < 0.13 mag in I-band. The variables cover
a broad range of reddening corrected colours, 1 < (V-I)_0 < 5, and a fairly
narrow range of extinction corrected apparent magnitudes, 10.5 < I_0 < 13 . A
subset of variables (type A) has a rms scatter of only 0.44 mag. The average
magnitudes for these stars are well correlated with the Galactic longitude, and
vary from I_{k,0} = 11.82 for l = +8 deg to I_{k,0} = 12.07 for l = -5 deg,
clearly indicating that they are located in the Galactic Bar. Most variables
have several oscillation periods.
