Schroeter was known to be close to Siemens CFO Joe Kaeser, who was quoted in a German paper last year as saying that NSN should have talked to German labour leaders before cutting jobs there.
NSN gave no reason for the departure, effective immediately, except to say it was part of a company transformation. It appointed chief operating officer Samih Elhage as successor.
Officials at the joint venture owners, Siemens and Finland's Nokia, were not immediately available for comment. NSN is led by Rajeev Suri in Finland.
The equipment maker has shown signs of a turnaround in recent quarters, helped by a massive restructuring drive last year that cut around 20,500 out of 74,000 jobs.
Nokia and Siemens have been looking to exit the joint venture through a buyout or public offering. Analysts expect a decision in the next few months.
Elhage joined NSN in March 2012, and has experience in private equity and management consulting, NSN said.
© Thomson Reuters 2013