Context :

Aims : Galactic globular clusters harbour binary systems that are detected as faint X-ray sources .
These close binaries are thought to play an important role in the stability of the clusters by liberating energy and delaying the inevitable core collapse of globular clusters .
The inventory of close binaries and their identification is therefore essential .

Methods : We present XMM- Newton observations of two Galactic globular clusters : NGC~2808 and NGC~4372 .
We use X-ray spectral and variability analysis combined with ultra-violet observations made with the XMM- Newton optical monitor and published data from the Hubble Space Telescope to identify sources associated with the clusters .
We compare the results of our observations with estimates from population synthesis models .

Results : Five sources out of 96 are likely to be related to NGC~2808 .
Nine sources are found in the field of view of NGC~4372 , none being located inside its half-mass radius .
We find one quiescent neutron star low mass X-ray binary candidate in the core of NGC~2808 , and propose that the majority of the central sources in NGC~2808 are cataclysmic variables .
An estimation leads to 20 \pm 10 cataclysmic variables with luminosity above 4.25 \times 10 ^ { 31 } \mathrm { ~ { } erg~ { } s } ^ { -1 } .
Millisecond pulsars could also be present in the core of NGC~2808 , and some sources outside the half-mass radius could possibly be linked to the cluster .

Conclusions :