Jim Collas has resigned as president of Amiga after less than nine months on the job.
It was not clear why Collas left the post. A spokesman for the company said Collas had resigned to pursue personal interests. Amiga said it had promoted vice-president and chief operating officer, Tom Schmidt, to fill the vacancy.
Separately, Collas registered to sell 118,000 shares of Gateway's common stock, according to forms released Wednesday by the US Securities and Exchange Commission.
The departure of Collas comes less than a month after the company orchestrated a high-profile coming-out party for the unit, which is a separate subsidiary of Gateway.
Gateway, which paid about $13 million (£8m) to acquire the rights to 47 Amiga patents, is attempting to revive the once-popular computer brand. Collas and other executives involved in the project had indicated interest in developing Internet-related products based around Amiga technology.
Collas, who held a variety of management posts during his seven years at Gateway, had eagerly pressed company CEO Ted Waitt and was subsequently granted the top job at Amiga in January of this year.
He also urged Waitt to let him run Amiga as a separate company.
Before joining Amiga, Schmidt worked as a general manager for Allied Signal, running one of the company's business units. He was not immediately available for comment.