SoftBank Group and Toyota Motor are leading a group of investors in talks to invest $1 billion or more into the unit.
That would give the unit a value of $5 billion to $10 billion, according to two people who told Reuters.
Uber's self-driving program has cost a lot of money and has not generated revenue.
News of investment talks was first reported by The Wall Street Journal, which said a deal could be reached next month.
It could also help underscore Uber's value as the ride-hailing firm prepares for a stock market debut.
The ride-hailing company could go public as early as May or June.
Uber and SoftBank declined to comment to Reuters, while Toyota said it didn’t have anything to announce.