DETROIT — Rivian, the startup electric vehicle manufacturer that is less than a year from launching its first two vehicles, is planning to transfer most of its engineering and product development staff from suburban Detroit to its battery systems and vehicle dynamics operation in Irvine, Calif.

Also, some of Rivian’s 750-strong Michigan work force will transfer to the company’s Normal, Ill., plant as the company gears up for production.

It’s unclear how many employees are moving out of Rivian’s offices in Plymouth, Mich.

Rivian spokeswoman Amy Mast confirmed some product development staff will be moving out of Michigan, but she said the company plans to keep some functions in its suburban Detroit facility. Rivian has eight facilities — six in the United States, one in Canada and one in the United Kingdom.

“Of Rivian’s 2,300 employees, approximately 1,000 are based in California and 750 in Michigan,” Mast told Automotive News in an e-mail. “We are consolidating some engineering teams to our locations in California to improve workflows and reduce environmental impact from travel.

“We’ve recently completed an expansion at our Michigan location, and it will remain an important presence for us. We are also committed to creating a vibrant and inviting manufacturing presence in Normal, where all Rivian vehicles will be produced. As we grow, we’ll keep evaluating and evolving our footprint and geography.”

The move was reported earlier by Autoline, a website and broadcast program that covers the Detroit auto industry.

Relocating the product development teams from Detroit to California comes as most of the design and engineering work on the company’s first two vehicles, the battery electric R1S sport utility and the R1T pickup, is nearly complete.

It also takes place as the company builds up its supplier base with Detroit-area parts makers.

This is not the first time Rivian has uprooted operations.

Rivian began as Avera Motors in Rockledge, Fla., on the state’s east coast in 2009. It took its current name from the Indian River near Cape Canaveral that runs near Rockledge. Rivian moved to Plymouth, Mich., in 2015, and began work on the R1T and R1S.

Rivian CEO RJ Scaringe “believes California is a cool place to be and Detroit has an old technology image,” a former Rivian executive told Automotive News. “He thinks California represents tomorrow and Detroit is all about yesterday.”

Mast, in an e-mail, said that statement was not accurate. “RJ believes that Michigan continues to be an amazing place for both business and talent,” she said in the e-mail. “We doubled our square footage in Plymouth over the past year.”

Since moving to Detroit, Rivian has hired a cadre of experienced designers and engineers — many from Ford Motor Co., General Motors and Fiat Chrysler Automobiles. It also has secured around $2.85 billion in financing from Amazon, Ford, Cox Automotive and an array of institutional investors. In December, the company landed a $1.3 billion investment round led by T. Rowe Price.

Autoline reported that some of Rivian’s staff were unhappy at the prospect of moving.

A Rivian employee familiar with the matter who declined to be identified told Automotive News that details of the relocation had not been shared with employees as of Tuesday afternoon.

“The timing of the moves is still being worked out. It’s not going to happen all at once. I will have to move and most of my team will have to move,” the person said.

Rivian has delayed the launch of the R1S and R1T from late this year to the first quarter of 2021 and is under pressure to begin filling an order for 100,000 electric vans placed by Amazon. Those deliveries are expected to begin in 2022.

Another project, a Lincoln electric SUV that Rivian was developing with Ford, was canceled earlier this year.

“Ford has a strategic and financial interest in Rivian, but they are an independent company,” said Ford spokesman T.R. Reid. He said Ford had no comment on Rivian’s plans.