Private equity-backed ProNerve has purchased rival PhysIOM Group LLC, a Fort Collins, Colo.-based provider of intraoperative neuromonitoring.

Terms of the deal were not disclosed.

ProNerve has been a portfolio company of Waud Capital Partners since February 2012. The Chicago firm invested in ProNerve out of its third fund, WCP Fund III.

PhysIOM, which serves over 290 hospital clients across 33 states, represents ProNerve’s third acquisition in 2012. The other two include Northwest Neurodiagnostics, which was also bought in February, and Intraoperative Monitoring Services, acquired in October.