We present the results of XMM-Newton observations of four high-z quasars , two radio-loud and two radio-quiet .
One of the radio-loud objects , PKS 2126 - 158 , clearly shows absorption in excess of the galactic value as claimed before from ASCA and ROSAT observations .
For PKS 2149 - 306 the evidence for excess absorption is only marginal in contrast to previous results .
The location of the absorber in PKS 2126 - 158 is compatible with the redshift of the source .
Both , a warm and a cold absorber are allowed by the X-ray data .
Both quasars have very flat photon spectra ( \Gamma~ { } \raise 2.15 pt \hbox { $ < $ } \kern - 8.0 pt \lower 2.845276 pt \hbox { $ \sim$ } ~ { } 1.5 ) and the high photon statistics reveal small deviations from a simple power law form .
For the two radio-quiet objects , Q 0000 - 263 and Q 1442+2931 , we determine , for the first time , reliable spectral parameters .
Both quasars have steeper power laws ( \Gamma \sim 2 ) and show absorption consistent with the galactic value , similar to radio-quiet quasars at low redshifts .
In the case of Q 0000 - 263 the presence of the damped Ly \alpha system ( N ( { HI } ) \sim 2.6 \times 10 ^ { 21 } cm ^ { -2 } at z = 3.39 ) can not be examined further due to the limited photon statistics in all instruments .