A pseudo-Stark splitting of the B1(20 993 cm-1) and the B2 (21 068 cm-1) absorption lines in ruby has been observed at 2°K. The splitting of each B line is 2.8×10-5 cm-1/V/cm for an electric field parallel to the c axis. This is a factor 3.7 larger than the corresponding splitting of the R lines. There is no observable effect for fields perpendicular to the c axis. Crystal-field theory satisfactorily predicts these properties, which are determined by the symmetry of the Cr3+ site. The point-charge model does not correctly predict the absolute value of the observed electric splitting, nor the matrix elements of the B lines.