  We present the identification of the optical counterparts to the low-mass
X-ray binaries 1A 1246-588 and 4U 1812-12. We determine the X-ray position of
1A 1246-588 from ROSAT/PSPC observations and find within the error circle a
blue star with V=19.45, B-V=0.22 and R-I=0.22 which we identify as the
counterpart. Within the Chandra error circle of 4U 1812-12, a single star is
present which appears blue with respect to the stars in the vicinity. It has
R=22.15, R-I=1.53. Distance estimates for both systems indicate that the
optical counterparts are intrinsically faint, suggesting that they are
ultra-compact X-ray binaries. These identifications would increase the number
of candidate ultra-compact X-ray binaries from 2 to 4, whereas orbital periods
are measured for only 7 systems in the Galactic disk.
