Tesla Inc. has parted ways with Jerome Guillen, a 10-year veteran who most recently served as president of heavy trucking and was one of four top executives running the company alongside Chief Executive Officer Elon Musk.

Guillen left the company June 3, according to a regulatory filing Monday. He was a top lieutenant to Musk and the brains behind the ramp up of Model 3 production in 2018. The executive previously served as president of Tesla’s automotive business, and was named head of heavy trucking in March of this year.

"That is a huge and unexpected loss,” Pierre Ferragu, an analyst at New Street Research who has a buy recommendation on the Tesla shares, said in an email. He added the news is part of a pattern of high-level executive departures at the company. "Jerome’s contribution to Tesla will remain part of the company and the company will continue to attract other top-guns.”

Tesla fell as much as 0.8% in postmarket trading Monday after closing up 1% to US$605.13 . The stock is down about 14% this year.

Guillen, who is French, joined Tesla in the fall of 2010 as the program director for the Model S, the breakthrough electric vehicle which laid the groundwork for the crossover Model X and more mass market Model 3 that followed. He was 48 years old as of Tesla’s latest annual report.

Guillen didn’t immediately respond to a request for comment.

Turnover Struggle

Tesla has struggled with executive turnover for years. Guillen took a several-months-long leave of absence from the company in 2015 but returned in 2016 to lead the company’s Semi truck program. He was promoted in 2018 to serve as the head of automotive operations.

The executive is known for building an assembly line against all odds in a tent outside of Tesla’s auto plant in Fremont, California. The cobbled-together line was instrumental to the company finally delivering on the Model 3, a bet-the-company effort that nearly bankrupted Tesla in 2018.

His sudden exit leaves Musk, Chief Financial Officer Zachary Kirkhorn and Drew Baglino, a senior vice president in charge of powertrain and energy engineering, as the triumvirate atop the company, which has more than 70,000 employees globally.

"We thank him for his many contributions and wish him well in his future career,” the electric carmaker said in the filing.

Guillen, who previously worked at Daimler AG, briefly appeared on stage when Tesla unveiled the Semi Truck in the fall of 2017. But initial production of the Semi has been delayed and is dependent on new, larger 4680 battery cells that Tesla is trying to make in-house and get from long-time suppliers like Japan’s Panasonic Corp.

Musk said via a tweet Sunday that Tesla has canceled plans to build a longer range version of its Model S known as the Plaid +, a vehicle that also was supposed to use the new type of battery.

Musk didn’t address whether the availability of the 4680 factored in Tesla’s decision to cancel the upscale version of the flagship sedan. Tesla will debut the standard Plaid model at an event scheduled to take place June 10.

 - Bloomberg