The embattled CEO of Motorola, Ed Zander, is to step down at the end of the year, as the company continues to battle declining sales and profits.

Motorola announced that Greg Brown, 47, its president and chief operating officer, will take over from Zander on 1 January. Meanwhile Zander, 60, will continue as the company's chairman until its shareholder meeting in May 2008, Motorola said.

"Next year marks my 40th year in the technology industry," Zander said in a statement. "This is the right time for me to move on to the next phase in my life and spend more time with my family."

Motorola has struggled this year in the mobile phone market, which accounts for about half of its business. Since launching its popular Razr handset a few years ago, Motorola has failed to come up with a new device that captures the public's imagination.

Just this week, research company Gartner said Motorola's share of the mobile phone market slid to 13 percent in the third quarter, down from 21 percent last year, and Motorola lost its second-place standing to South Korea's Samsung Electronics.

Motorola reported net sales of $8.8 billion for its third quarter, down from $10.6 billion a year ago. Net earnings were $60 million, down from $968 million in the same quarter a year earlier.

Zander became CEO of Motorola in January 2004. He was previously managing director at Silver Lake Partners, and before that was the long-time president and COO of Sun Microsystems.

Brown has been president and COO of Motorola since March, and led various divisions of the company since joining in 2003. Before that he was chairman and CEO of Micromuse, a network management software company.