TRW Automotive, headquartered in Livonia, Michigan was an American global supplier of automotive systems, modules and components to automotive original equipment manufacturers (OEMs) and related aftermarkets. In 2015 TRW Automotive was acquired by ZF Friedrichshafen and subsequently has been renamed ZF TRW Automotive Holdings Corp. TRW formally stood for "Thompson Ramo Wooldridge"; it was formed when Thompson Products merged with Ramo-Wooldridge in 1958. The company operated primarily surrounding the design, manufacture and sale of safety systems. It operated approximately 200 facilities with 66,100 employees in 26 vehicle-producing countries. When aerospace company Northrop Grumman purchased competitor TRW in 2002, it sold TRWs automotive division to private equity firm Blackstone Group. TRW Automotive went public in a February 2004 initial public offering (IPO), after which Blackstone held a 56.7% interest in TRW, Northrop Grumman, 17.2%, and TRW management, 1.7%. The company can trace its history back to TRW Incs beginnings in 1901, but was founded as TRW Automotive in 2002.