Uber says it will invest up to $1.25 billion in Rivian Automotive to help launch up to 50,000 robotaxis.

Uber, or its fleet partners, are expected to buy 10,000 fully autonomous Rivian R2 robotaxis, with the option to purchase up to 40,000 more in 2030.

The companies said Thursday that initial deployments of the vehicles are expected to begin in San Francisco and Miami in 2028 and will expand to 25 cities by 2031.

Uber's investment in Rivian will be spread out up to 2031 and is subject to hitting certain autonomous milestones by specific dates.

An initial $300 million investment has been committed to following the deal's signing, subject to regulatory approval.

In premarket trading, shares of Rivian rose 10%. Uber shares edged up less than 1%.