In this work, results on the Ba...FCH3 + hnu --> BaF (Ba+) + CH3 (CH3F) reaction obtained under high laser field conditions are reported. We have found that the two-photodissociation channel yields, i.e. the reactive BaF and non-reactive Ba* products, exhibited opposite behaviour depending upon the laser fluence. Whereas the BaF yield rises as the laser fluence is increased, the Ba* yield decreases over the same laser fluence range. In other words, the product (Ba*)/(BaF) branching ratio changes significantly from low to high laser fluence in such a way that the (photoinitiated) Ba...FCH3 --> BaF + CH3 reaction may be controlled by changing the intensity of the excitation laser field. (C) 2002 Elsevier Science B.V. All rights reserved.