(Bloomberg) -- Tesla Inc. lost one of its senior manufacturing executives months ago, according to a person familiar with the matter, a loss that lengthens the list of departures during a harried period for the electric-car maker led by Elon Musk.

Gilbert Passin, Tesla’s vice president of manufacturing, left this summer, said the person, who asked not to be identified discussing personnel matters. Passin joined Tesla from Toyota Motor Corp. in early 2010.

Retaining senior managers has been one of Musk’s biggest challenges this year. While Tesla has made major strides lately with manufacturing more electric vehicles, the chief executive officer has been the source of major distractions, including a short-lived and legally precarious attempt to take the company private.

Other executives who’ve left Tesla in recent months include the company’s chief accounting officer, the vice presidents of global supply management and worldwide finance, and the heads of human resources and communications.

Musk announced a series of promotions in September to fill several voids and named Jerome Guillen to the new position of automotive president. The CEO has credited Guillen with helping the company achieve production progress with the Model 3 sedan, which may have recently exceeded the 100,000 mark after months of missed targets.

Business Insider reported on Passin’s departure earlier Wednesday.

To contact the reporter on this story: Dana Hull in San Francisco at dhull12@bloomberg.net

To contact the editors responsible for this story: Craig Trudell at ctrudell1@bloomberg.net, Melinda Grenier

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