  We report the discovery by the CoRoT satellite of a new transiting giant
planet in a 2.83 days orbit about a V=15.5 solar analog star (M_* = 1.08 +-
0.08 M_sun, R_* = 1.1 +- 0.1 R_sun, T_eff = 5675 +- 80 K). This new planet,
CoRoT-12b, has a mass of 0.92 +- 0.07 M_Jup and a radius of 1.44 +- 0.13 R_Jup.
Its low density can be explained by standard models for irradiated planets.
