Deutsche Beteiligungs, the German mid-market buy-out firm, has bought Preh Werke, an electronics subsidiary of automotive and defence group Rheinmetall, and persuaded a member of the Preh founding family to reinvest alongside it.

Deutsche Beteiligungs declined to disclose the price but said the company generates sales of €220m ($260m) and employs 1,700 staff. It provides sensor systems for cars and its customers include BMW, DaimlerChrysler and General Motors.