Uber Technologies has filed paperwork for an initial public offering, according to three people with knowledge of the matter. : (Reuters) — Uber Technologies 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 Thursday, one of the sources said, in lock-step with its smaller U.S. rival, Lyft, which also announced on Thursday it had filed for an IPO.