Uber will invest $300 million in electric vehicle maker Lucid in a robotaxi deal that aims to start with one major U.S. city late next year, the companies said on Thursday.

The partnership will combine Uber's ride-sharing platform with Lucid's new electric SUV, the Gravity, and Nuro's autonomous driving technology. It'll be launching first in an unnamed "major US city," but is expected to roll out globally to more than 20,000 Lucid vehicles over the next six years.