Stu Reed, president of Motorola's troubled mobile device business, has left the company with immediate effect, an Associated Press report said.
It quoted a spokeswoman saying that Reed had been preparing for his departure after Motorola announced that CEO Greg Brown would take direct control of the division last month. Reed had led the division since last summer.
The spokeswoman said she did not know Reed's plans.
Motorola shares soared last month when the company said it may sell the mobile division, which accounted for â‚¬12.35 billion/US$19 billion of Motorola's â‚¬23.79 billion/US$36.6 billion in sales last year.
The company's mobile phone profit margin and sales slipped last year, and the company fell to third place on the global mobile market, overtaken by Samsung Electronics, with Nokia remaining in the top spot.
Reed's was the second executive departure announced this week as Motorola struggles to win back Wall Street's confidence.