* Jorge Gomez Diaz to take up new post on Dec. 19
* Copper output at world No.3 copper mine tumbling
* Turning around operation seen a challenge
SANTIAGO, Oct 30 (Reuters) - The world's No.3 copper mine, Collahuasi, said on Tuesday it has appointed as its new chief executive Codelco's vice president for central-south operations, Jorge Gomez Diaz, in a push to turn around the troubled Chilean operation.
Last year Collahuasi was dragged to its lowest copper output since 2007 and has been hit this year by a combination of work stoppages, heavy rains and fatal accidents, prompting Anglo , Xstrata and Japanese partner Mitsui to step in, appointing interim co-chief executives and a recovery plan.
"During this period, Collahuasi has undergone a thorough restructuring as part of a process agreed by the company's shareholders and the board is confident that, under Jorge Gomez, the progress achieved during this intervention will continue so that the operation achieves its full potential," the mine said in a statement.
Gomez, a mining engineer, will take up his new post on Dec. 19. He has more than 20 years of experience, including a five-year stint as vice president of operations at Antofagasta Minerals, Collahuasi added.
From January to August, output at Collahuasi tumbled 37.9 percent from the same period of last year, according to figures from Chile's Cochilco copper commission.
The potential expansion of Collahuasi, which accounted for just over a fifth of Xstrata's copper production last year, is one of the world's largest copper growth projects yet to get the final green light from their owners, and could more than double annual output from the mine.