Sherri Welch - UK-based Impellam Group plc has entered an agreement to acquire Southfield-based Bartech Holding Corp. and its subsidiary Bartech Group Inc. for $120 million in cash and debt. The deal closed Wednesday. Bartech, a global managed services provider, had been majority-owned by Sverica Capital Management LLC, a private equity firm, since March 2012. For Impellam, the deal represents an “exciting opportunity to create top line growth by achieving increased market share at strong margins and