  We present detailed spectral and timing analysis of the hard x-ray transient
IGR J16358-4726 using multi-satellite archival observations. A study of the
source flux time history over 6 years, suggests that lower luminosity transient
outbursts can be occuring in intervals of at most 1 year. Joint spectral fits
of the higher luminosity outburst using simultaneous Chandra/ACIS and
INTEGRAL/ISGRI data reveal a spectrum well described by an absorbed power law
model with a high energy cut-off plus an Fe line. We detected the 1.6 hour
pulsations initially reported using Chandra/ACIS also in the INTEGRAL/ISGRI
light curve and in subsequent XMM-Newton observations. Using the INTEGRAL data
we identified a spin up of 94 s (dP/dt = 1.6E-4), which strongly points to a
neutron star nature for IGR J16358-4726. Assuming that the spin up is due to
disc accretion, we estimate that the source magnetic field ranges between 10^13
- 10^15 G, depending on its distance, possibly supporting a magnetar nature for
IGR J16358-4726.
