The propagation of an initially planar front is studied within the framework of the photosensitive Belousov-
Zhabotinsky reaction modulated by a smooth spatial variation of the local front velocity in the direction
perpendicular to front propagation. Under this modulation, the wave front develops several fingers corresponding
to the local maxima of the modulation function. After a transient, the wave front achieves a stationary
shape that does not necessarily coincide with the one externally imposed by the modulation. Theoretical
predictions for the selection criteria of fingers and steady-state velocity are experimentally validated.