We study the multiphoton dissociation of H-2+ by a coherent superposit
ion of an intense short pulsed laser radiation and one of its harmonic
s (second or third), in a phase-locked regime. We show that the total
dissociation probability, the energy distribution, and the direction o
f ejection of the protons are very sensitive to the relative phase of
the two radiations. A high degree of control may thus be achieved for
the branching ratio between dissociation via bond-softening and above-
threshold dissociation, in the realm of current experimental capabilit
ies.