  A 0.5-200 keV BeppoSAX spectrum of the non-pulsating high-mass X-ray binary
4U1700-37 is presented. The spectrum is well characterized by the standard
accreting pulsar model of an absorbed power-law with a photon index of 1.07
+0.02 -0.03, sharply modified by an exponential cutoff above 5.9 +/- 0.2 keV.
The e-folding energy of the cutoff is 23.9 +/-0.5 keV. A soft bremsstrahlung
component with a temperature of 0.2 +/- 0.1 keV is also required, together with
a narrow iron line at 6.5 keV. Both continuum components are absorbed by a
column of (5.1 +/- 0.2) x 10E22 atom/cm2. There is some evidence for the
presence of a broad cyclotron absorption feature at ~37 keV, although we cannot
exclude the possibility that this is due to an incorrect modeling of the
continuum, or instrumental effects. The hypothesis that the compact object is a
neutron star rather than a black hole seems most likely.
