Mike Devereux, a top GM sales and marketing executive in China, took over as vice president, OnStar safety and security, as of Nov. 1, a GM spokeswoman told Automotive News.
Devereux succeeds Massimilla, who had overseen OnStar since September 2021. GM did not comment on Massimilla's departure.
Devereux began working for GM in 1984 and has had multiple leadership roles, most recently as vice president for vehicle sales, service and marketing for GM China and SAIC-GM, a joint venture with SAIC Motor Corp., according to the automaker.
Massimilla did not immediately respond to a message seeking comment Wednesday. In July, he introduced a new brand identity and logo for OnStar aimed at increasing the reach of its services.
His previous roles at GM included vice president for global cybersecurity, vehicle safety chief and director of global validation.