Trapped between a rock and a hard place, Motorola's new CEO Greg Brown is presiding over a new exodus of top executives while billionaire investor Carl Icahn increases pressure to break up the company and sell off the pieces.

Brown wants to sell off pieces of the company, too, but it's unclear whether anyone wants to pay what Brown and Icahn think they are worth. Nokia, Samsung, and LG Electronics -- all gaining handset market share on Motorola -- have said they aren't interested. And the once-glamorous mobile phone device market is now overcrowded. Last week, Mitsubishi said it would dispose of its unprofitable mobile-phone business and in January, Sanyo Electric said it, too, will leave the mobile phone business.

Motorola announced late Friday that Stu Reed, who had been in charge of Motorola's Mobile Devices unit, would leave the company "effective immediately." Last month, Brown had taken over direct control of the Mobile Devices unit from Reed, who had run the operation for just a few months well after Motorola's handset market share began declining.

Just days before Reed's departure, it was revealed that the company's top marketing leader, Kenneth "Casey" Keller, had left the firm.

Motorola has formed a partnership with Qualcomm to develop future mobile phone technologies for service providers and it has been in talks with Nortel Networks to form a partnership on wireless infrastructure technologies that would be run by Nortel

Motorola is now girding for a proxy battle at its May 5 annual meeting with Icahn, who has proposed a slate of candidates for Motorola's board. Icahn's candidates are: Frank Biondi Jr., former Viacom executive; William Hambrecht of the eponymous investment banking firm; MIT professor Lionel Kimerling; and Keith Meister, an executive at Icahn's funds. Icahn recently raised his stake in Motorola to 6.5%

Icahn lost a proxy fight last year when CEO Ed Zander was at the helm of Motorola. Brown took over from Zander earlier this year.

At a meeting of equity investors in New York last week, Icahn said he still likes Motorola as an investment, according to a Wall Street Journal report. "We just like it," said Icahn. "It's extremely cheap. Everything they can do wrong, they did it wrong... The rest of the company is doing darn well."