The Iron Bears was a private military contractor based out of Russia and other Slavic, Baltic states (as most of the mercs have Russian accents) employed by Weyland-Yutani to "baby sit" and provide security for the personnel and assets on LV-1201. They fought galliantly, but the Xenomorph infestation was more than they could handle and a number of the "Corporates" were killed or captured by the Xenomorphs.