GRB 040403 is one of the faintest gamma-ray bursts for which a rapid and accurate localization has been obtained .
Here we report on the gamma-ray properties of this burst , based on observations with the IBIS instrument aboard INTEGRAL , and the results of searches for its optical afterglow .
The steep spectrum ( power law photon index = 1.9 in the 20-200 keV range ) implies that GRB 040403 is most likely an X-ray rich burst .
Our optical limit of R > 24.2 at 16.5 hours after the burst , indicates a rather faint afterglow , similar to those seen in other relatively soft and faint bursts .