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. He was a top lieutenant to Musk and played a key role in ramping up 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.

“That is a huge and unexpected loss,” Pierre Ferragu, an analyst at New Street Research who has a buy rating on Tesla shares, said in an email. “Jerome’s contribution to Tesla will remain part of the company and the company will continue to attract other top-guns.”

Tesla pared an early gain Tuesday of as much as three per cent to trade up 1.6 per cent to US$614.74 as of 10 a.m. in New York. The stock rallied in premarket trading after China’s Passenger Car Association said deliveries rebounded in May.

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

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

High Turnover

Tesla has dealt 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 lead auto operations.

The executive is known for building a makeshift assembly line in a tent outside of Tesla’s auto plant in Fremont, California, that was instrumental to the company resolving early stumbles with the Model 3, a bet-the-company effort that almost bankrupted Tesla in 2018.

“Tesla’s executive team has historically exhibited what we perceive to be a higher-than-average rate of turnover and -- as such -- are not overly concerned about these departures,” Ben Kallo, a Robert W. Baird analyst who rates the company the equivalent of a buy, wrote in a report.

Guillen’s 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,” Tesla said in its filing Monday.

Semi Delays

Guillen, who previously worked at Daimler AG, briefly appeared on stage when Tesla unveiled the Semi in the fall of 2017. But initial production of the truck has been delayed and is dependent on new, larger 4680 battery cells that Tesla is trying to make in-house along with long-time supplier Panasonic Corp.

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

The CEO 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 for June 10.