Kalanick told Uber employees earlier in March that he's looking for "a peer who can partner with me to write the next chapter in our journey."
Board member Arianna Huffington told reporters in a conference call on Tuesday that Uber was in the midst of interviewing candidates, and was looking for a leader with significant experience who can thrive in a hyper-growth company. She said she and Gurley had met with world-class leaders.
Armstrong, Staggs and Martin have all seen overseen major structural and financial overhauls to their organizations. Armstrong has united AOL, The Huffington Post, and soon, Yahoo, under Verizon. Staggs presided over Disney's integration of ABC, Pixar and Marvel. And Turner has endured a series of changes under Time Warner, and soon, AT&T.
The fact that all three reported candidates are men could cause controversy, given that the company is conducting an investigation into allegations from former engineer Susan Fowler of sexism and harassment at the company. The company's difficult month has also included a patent infringement lawsuit from Alphabet's self-driving car business, Waymo, and run-ins with regulators and drivers. (Here's a timeline of exactly what's gone on.)
Uber President Jeff Jones, the company's previous number-two, recently stepped down, citing the "beliefs and approach to leadership" at the company. Jones found Kalanick to be "headstrong, pugnacious and hard-partying," a person familiar with Jones' thinking told Bloomberg.
Bloomberg reported that Jones supported in-app tipping for Uber drivers, and worried that Uber's auto leasing program could attract reckless drivers. Uber now says it is trying to improve its relationship with drivers.
— With reporting by CNBC's Deirdre Bosa