What began as alleged “choking and punching” by Ohio management lawyer Stephen J. Sferra during testy contract negotiations with a Teamsters Union attorney in 2006 has escalated into a civil suit filed last week by the union lawyer on the receiving end.

The lawsuit by attorney John M. Masters has now dragged employment firm Littler Mendelson’s Cleveland office into the fray as a named party because the San Francisco-based Littler took over Sferra’s firm, Duvin Cahn & Hutton, after the altercation.