  X-ray quasi-periodic oscillations (QPOs) in AGN allow us to probe and
understand the nature of accretion in highly curved space-time, yet the most
robust form of detection (i.e. repeat detections over multiple observations)
has been limited to a single source to-date, with only tentative claims of
single observation detections in several others. The association of those
established AGN QPOs with a specific spectral component has motivated us to
search the XMM-Newton archive and analyse the energy-resolved lightcurves of 38
bright AGN. We apply a conservative false alarm testing routine folding in the
uncertainty and covariance of the underlying broad-band noise. We also explore
the impact of red-noise leak and the assumption of various different forms
(power-law, broken power-law and lorentzians) for the underlying broad-band
noise. In this initial study, we report QPO candidates in 6 AGN (7 including
one tentative detection in MRK~766) from our sample of 38, which tend to be
found at characteristic energies and, in four cases, at the same frequency
across at least two observations, indicating they are highly unlikely to be
spurious in nature.
