Google is preparing to offer its own ride-hailing service, putting it in direct competition with Uber, Bloomberg News reported, citing a person close to Uber's board.
Google is one of the biggest investors in Uber.
David Drummond, Google's chief legal officer and a member of Uber's board, has informed Uber of Google's plans, Bloomberg reported.
The source also said Uber's board was weighing whether to ask Drummond to resign, Bloomberg reported.
Uber executives have been made privy to screenshots of Google's ride-sharing app, which is currently being used by Google's employees, Bloomberg reported.
Google's move may imperil Uber's reliance on the search giant, as the cab service's smartphone applications for drivers and riders are based on Google Maps.
Both Uber and Google were not available for comment.