A group of investors led by SoftBank Group Corp. and Toyota Motor Corp. is in talks to invest $1 billion or more into Uber Technologies Inc.'s self-driving vehicle unit, which would value the unit at $5 billion to $10 billion, said two people familiar with the talks. The investment would provide a cash injection for Uber's self-driving program, which is costing the money-losing startup hundreds of millions of dollars without generating revenue. It could also help underscore Uber's value as the ride-hailing firm prepares for a stock market debut in which its value could top $100 billion. Uber and SoftBank declined to comment. A Toyota spokesman said the automaker "constantly reviews and considers various options for investment" but does not have anything to announce.