First Solar environmental head to leave company

* Head of environmental affairs, legal division to leave

* Departure effective Dec. 1

* Existing executive staff to pick up divisions

LOS ANGELES, Nov 17 (Reuters) - U.S. solar company First Solar Inc (FSLR.O) said on Tuesday its executive vice president of environmental and legal affairs will leave at the end of the month, marking the latest in string of management changes.

First Solar, the largest solar power company in the United States, said in a U.S. Securities and Exchange Commission filing that the executive, John Gaffney, and the company had "mutually agreed" on the departure effective Dec. 1.

The executive's severance package will cost the company $6.9 million in net income in the fourth quarter.

The departure resulted from recent organizational changes made by the company's new chief executive Robert Gillette, First Solar spokesman Alan Bernheimer said.

Various members of the company's executive staff will share Gaffney's areas of responsibility, Bernheimer said.

Gaffney led First Solar's sustainable development and environmental affairs as well as its legal and corporate development departments, according to the company's website.

Before joining First Solar, Gaffney was a partner at the law firm Cravath, Swaine & Moore LLP.

His departure follows the exit of First Solar's global marketing head in August and the naming of Gillette in September to replace chief executive Michael Ahearn after a four-month search. [ID:nN26281365] [ID:nN03119071]

Shares of First Solar was slightly up at $124.44 in early afternoon trading on the Nasdaq on Tuesday. (Reporting by Laura Isensee, editing by Leslie Gevirtz)