DETROIT – Rivian Automotive is laying off roughly 4.5% of its workforce as the all-electric vehicle maker faces growing market challenges, according to a note sent to employees Thursday and viewed by CNBC.

In the message, Rivian founder and CEO RJ Scaringe said the cuts largely involved restructurings of its marketing, vehicle operations and sales/delivery and mobile operations teams.

“These are not changes that were made lightly. With the changing operating backdrop, we had to rethink how we are scaling our go-to-market functions. This news is challenging to hear, and the hard work and contributions of the team members who are leaving are greatly appreciated,” Scaringe said.

Rivian had just under 15,000 employees at the end of last year.

The note did not specify how many employees would be laid off. The Wall Street Journal, which first reported the plans, said the layoffs would affect more than 600 workers, which a source familiar with the plans confirmed to CNBC. The person spoke anonymously because the news had not yet been made public.

Rivian and other EV manufacturers are increasingly facing a more challenging market than they did in recent years amid changing regulations under the Trump administration, including the elimination of a $7,500 federal incentive for purchasing an EV.

Aside from regulatory issues, Rivian also faces slower-than-expected EV demand and a lack of new products until next year amid needs for cash and earnings losses. The company lost $1.1 billion during the second quarter.

Scaringe, in the Thursday note, said the changes will ensure the company “can deliver on our potential by scaling efficiently towards building a healthy and profitable business,” as it prepares to launch its new R2 models, which are expected to begin production next year.

Rivian’s vehicle sales increased 32% to 13,201 units year over year during the third quarter as buyers hurried to purchase an EV before the federal incentives expired at the end of September, but the company’s 2025 delivery forecast was narrowed from as many as 46,000 units to between 41,500 and 43,500 vehicles.

In August, Rivian also flagged a bigger adjusted core loss this year, expecting it to between $2 billion and $2.25 billion, compared with $1.7 billion to $1.9 billion previously forecast.

Shares of Rivian closed Thursday at $13.09, up 1.3%. The stock is off less than 2% this year.