We present results based on an XMM-Newton observation of the high luminosity narrow-line QSO PHL 1092 performed in 2003 January .
The 0.3 - 10 keV spectrum is well described by a model which includes a power-law ( \Gamma \sim 2.1 ) and two blackbody components ( kT \sim 130 eV and kT \sim 50 eV ) .
The soft X-ray excess emission is featureless and contributes \sim 80 \% to the total X-ray emission in the 0.3 - 10 keV band .
The most remarkable feature of the present observation is the detection of X-ray variability at very short time scale : the X-ray emission varied by 35 % in about 5000 s. We find that this variability can be explained by assuming that only the overall normalization varied during the observation .
There was no evidence for any short term spectral variability and the spectral shape was similar even during the ASCA 
observation carried out in 1997 .
Considering the high intrinsic luminosity ( \sim 2 \times 10 ^ { 45 } erg s ^ { -1 } ) and the large inferred mass of the putative black hole ( \sim 1.6 \times 10 ^ { 8 } M _ { \sun } ) , the observed time scale of variability indicates emission at close to Eddington luminosity arising from very close to the black hole .
We suggest that PHL 1092 in particular ( and narrow line Seyfert galaxies in general ) is a fast rotating black hole emitting close to its Eddington luminosity and the X-ray emission corresponds to the high-soft state seen in Galactic black hole sources .