Ford executives declined to say what type of vehicle the company would develop on Rivian's skateboard platform, where it would be built or when it would go on sale. They said it would not be one of the two battery EVs Ford has already announced. Hackett said the Rivian investment was in addition to Ford's $11 billion financial commitment to electrifying its lineup through 2022.

"Ford's investment in Rivian is a smart one," Michelle Krebs, executive analyst at Autotrader, said in a statement. "Rivian leverages Ford's leadership, expertise and massive volume in pickup trucks as well as its vast distribution network. The Amazon investment in the Rivian mix may well give Ford an in with the delivery services, possibly with electric cargo vans."

Rivian, which has shown concept versions of an electric pickup and SUV, will remain an independent company, and the investment is subject to regulatory approval. Joe Hinrichs, Ford's president of automotive, will join Rivian's seven-member board.

Rivian's founder and CEO, RJ Scaringe, said the startup plans a "broad portfolio" of vehicles on its skateboard architecture, some of which might directly compete with Ford's EVs. But he said vehicles it develops with Ford will be distinct, with Rivian focused on higher-priced performance models in the active lifestyle space.

"What we do with Ford will be different than that," Scaringe said.

Scaringe said Rivian could partner with other companies, although its current focus would be on building the relationships with its existing partners.

Hinrichs said the deal allows Ford to save money and speed up the arrival of its upcoming crossover EV, and he left open the possibility that the partnership could broaden beyond one vehicle, saying this was the "first of many pieces of news" he hoped both companies would share.