4U 2206+54 is a high mass X-ray binary which has been suspected to contain a neutron star accreting from the wind of its companion BD +53 \arcdeg 2790 . Reig et al .
( 27 ) have recently detected 5560 s period pulsations in both RXTE and INTEGRAL observations which they conclude are due to the spin of the neutron star .
We present observations made with Suzaku which are contemporaneous with their RXTE observation of this source .
We find strong pulsations at a period of 5554 \pm 9 s in agreement with their results .
We also present a reanalysis of BeppoSAX observations of 4U 2206+54 made in 1998 , in which we find strong pulsations at a period of 5420 \pm 28 seconds , revealing a spin-down trend in this long-period accreting pulsar .
Analysis of these data suggests that the neutron star in this system is an accretion-powered magnetar .