CO molecules in a supersonic molecular beam are resonantly excited from the X 1SIGMA+, upsilon" = 0 ground state to the a 3PI, upsilon' = 0 metastable state using pulsed laser radiation at 206 nm. In the excitation region a static electric field is applied to split individual M components of a given rotational line of this electronic transition. The splitting can be made larger than the Fourier-limited bandwidth of the pulsed radiation source and specific M levels in the a 3PI state can be populated. Peak fluxes of 10(17) (10(15)) oriented CO a 3PI1, upsilon' = 0, J' = 1, M' = 1 (a 3PI2, upsilon' = 0, J' = 2, M' = 2) molecules per second are obtained.