NEW YORK/SAN FRANCISCO—Uber Technologies Inc. has filed paperwork for an initial public offering, according to three people with knowledge of the matter, taking a step closer to a key milestone for one of the most closely watched and controversial companies in Silicon Valley.
The ride-hailing company filed the confidential paperwork on Dec. 6, one of the sources said, in lock-step with its smaller U.S. rival, Lyft Inc., which also announced on Dec. 6 it had filed for an IPO.





