Kalanick's decision "was a surprise to everyone", a second Uber spokesman said.
Mr Kalanick, who had been on indefinite leave amid criticism of his management style and after the death of his mother in a boat accident, said: "I love Uber more than anything and at this hard moment in my personal life I have accepted the investors" request to step aside so that Uber can go back to building rather than be distracted with another fight'.
The 40-year-old's pugnacious style largely defined Uber's approach and helped it become a transport colossus valued at US$68 billion (RM291.7 billion), the largest private firm backed by venture capitalists in the world.
Venture capital firm Benchmark, whose partner Bill Gurley is one of Uber's largest shareholders and sits on its board, as well as investors First Round Capital, Lowercase Capital, Menlo Ventures and Fidelity Investments, all pressed Kalanick to quit. By stepping away, he's taking the time to heal from his personal tragedy [the sudden death of his mother] while giving the company room to fully embrace this new chapter in Uber's history.
Not long after, former Uber engineer Susan Fowler published a blog post describing her experiences of sexism at Uber.
This month, the company shared the recommendations of an investigation it commissioned into workplace culture problems by the law firm of former US Attorney General Eric Holder.
A person close to Sheryl Sandberg tells The Associated Press that the Facebook chief operating officer has no plans to leave the company.
The changes come as Uber works to fix the damage to its reputation following an investigation into allegations of sexual harassment, bullying and other employee concerns.
Uber has also run into some serious troubles in India in the recent past. Kalanick has been humbled by recent events, which included the release of a dash-cam video showing him berating and cursing at one of Uber's drivers. The lawsuit cites several media reports where Kalanick and other executives doubted the victim's account of rape.
Last year, an Uber driver was arrested in Kolkata over allegations of sexually assaulting a woman inside the cab.