The company's board confirmed the move early Wednesday, saying in a statement that Kalanick is taking time to heal from the death of his mother in a boating accident "while giving the company room to fully embrace this new chapter in Uber's history." He will remain on the Uber Technologies Inc. board.
The move comes at a pivotal time for the largest ride-hailing company. After eight years of phenomenal growth by upending the taxi business, Uber had reached a point where the free-wheeling culture that created the company had become an albatross that threatened to kill it.
RELATED: Uber CEO takes leave of absence on same day company culture report released
In a statement, the 40-year-old co-founder said his resignation would help Uber go back to building "rather than be distracted with another fight," an apparent reference to efforts on the board to oust him.
The resignation came after a series of costly missteps under Kalanick. Uber on Tuesday embarked on a 180-day program to change its image by allowing riders to give drivers tips through the Uber app, something the company had resisted under Kalanick.
The San Francisco-based company is trying to reverse damage done to its reputation by revelations of sexual harassment in its offices, allegations of trade secrets theft and an investigation into efforts to mislead government regulators.
Uber's board said in a statement that Kalanick had "always put Uber first."
While growing from a small startup, Uber developed a reputation for ruthless tactics that have occasionally outraged government regulators, drivers, riders and its employees.
The company's hard-charging style has led to legal trouble. The U.S. Justice Department is investigating Uber's past usage of phony software designed to thwart local government regulators who wanted to check on whether Uber was carrying passengers without permission.
Uber also is fighting allegations that it relies on a key piece of technology stolen from Google spin-off Waymo to build self-driving cars.
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MORE: Kalanick's resignation comes amid decision by Uber shareholders who pushed for his exit. https://t.co/4WmuEnoYBF— ABC News (@ABC) June 21, 2017