First Solar Inc (FSLR.O) on Tuesday said the head of its utility systems business, Jens Meyerhoff, is leaving the company, effective Sept. 30.

James Brown, senior vice president of utility systems business sales, will succeed Meyerhoff in the utility-scale solar unit and will report to Chief Executive Rob Gillette.

Meyerhoff, who served as the company's chief financial officer for four years before being tapped to lead the fast-growing utility unit, did not give a reason for his departure.

"The company has now reached a size and scale that allows me to step back and self-reflect before deciding my next step in life," he said in a statement. He noted several recent milestones in the company's U.S. utility-scale solar business, including the sale of its 290 megawatt Agua Caliente project in Arizona to NRG Energy Inc (NRG.N) and the start of construction on its 550 MW Desert Sunlight power plant in California.

Meyerhoff joined the company as CFO in 2006 and became president of its newly created utility systems unit slightly more than a year ago in July of 2010.

"It's a little surprising considering the fact that he just fairly recently took on the job as president of the company's utility business," said Brigantine Advisors analyst Ramesh Misra. "He was the CFO for a long time and most of the Street knew him as the CFO. Moving over to the utility business went to show how much importance the company accorded its utility business."

His departure is the latest of several management shifts at the world's most valuable solar company since longtime CEO Mike Ahearn stepped down from that post in late 2009 and handed over the reins to Honeywell Aerospace (HON.N) veteran Gillette.

Most recently, the company's president of operations, Bruce Sohn, left the company in April to pursue other opportunities. He is now CEO of energy storage startup Fluidic Energy.

A month before that, First Solar appointed Mark Widmar as its new finance chief, replacing interim CFO James Zhu. Zhu is now the company's chief accounting officer.

As part of the management transition, Frank DeRosa will become the utility business's senior vice president of business development for the Americas, First Solar said.