Uber's new Chief Executive Dara Khosrowshahi has told employees the ride-services company will change its culture and may go public in 18 to 36 months.

Khosrowshahi, who led travel-booking site Expedia for 12 years, made the remarks as he introduced himself to Uber's workforce on Wednesday during an all-staff meeting at its San Francisco headquarters.

With a $US68 billion ($86 billion) valuation by private investors, Uber is the most valuable startup Silicon Valley has produced over the last decade, but funders have grown frustrated by the lack of a timeline for getting their payouts. Employees have also felt pent up, as many are compensated with options in the company.

The loose IPO timeline gives Khosrowshahi an opportunity to resolve many of the controversies facing the company. That includes litigation with Google in a major case in which Uber is accused of stealing trade secrets from Google's self-driving car program, as well as two pending federal investigations.

On Tuesday, the company confirmed that the Department of Justice is probing whether executives broke US laws prohibiting bribery of officials in foreign countries. Uber is cooperating with the investigation, a spokesman Matt Kallman said.

Under its previous hard-charging chief executive, Travis Kalanick, Uber expanded to 77 countries in just eight years and built up a reputation for rule-breaking and for a "bro" culture that has been hostile to women and underrepresented minorities. Federal officials are also probing whether the company used special software to evade authorities in places where ride-sharing services were banned or restricted

Uber 'has to change'

"This company has to change," Khosrowshahi told employees, according to the Twitter feed of Uber's communications team. "What got us here is not what's going to get us to the next level."

Khosrowshahi said Uber needed to stabilise itself but also take what he called "big shots."

The appointment of Khosrowshahi, who described himself as "a fighter," comes as Uber is trying to recover from a series of crises that culminated in the ouster of its former CEO Travis Kalanick in June. It is also a key step toward filling a gaping hole in its top management that at the moment has no chief financial officer, head of engineering or general counsel.

In his first meeting with Uber employees, Khosrowshahi emphasised recruiting new talent - particularly a chief financial officer - as well as a chairman to help him run the board, according to tweets from Uber.

Board room battle

Khosrowshahi inherits a dysfunctional board that has been divided by a lawsuit filed by investor Benchmark Capital against Kalanick. The lawsuit, which seeks to force Kalanick off the board and rescind his ability to fill two board seats, has caused shareholder infighting and complicated the CEO search.

Delaware judge Sam Glasscock on Wednesday brought that dispute closer to a resolution when he stayed the lawsuit and moved it to arbitration, which moves the legal fight out of the public eye.

"I think what we have here is a political battle that belongs in the boardroom and not the courtroom," said Donald Wolfe, an attorney for Kalanick.

Glasscock stopped short of dismissing the lawsuit, as Kalanick had requested, because of concerns about the impact the dispute might have on other Uber shareholders who may also want to take legal action.

America's most expensive CEO?

The board had already selected Khosrowshahi as Uber's next CEO in a vote on Sunday. But the firm and its board did not speak publicly on the decision until Tuesday evening, as contract negotiations were ongoing.

"The board and the executive leadership team are confident that Dara is the best person to lead Uber into the future," Uber's eight-member board wrote in an email to employees sent late on Tuesday that was also made public.

Kalanick, who attended Wednesday's staff meeting, welcomed his replacement in a statement.

"Casting a vote for the next chief executive of Uber was a big moment for me and I couldn't be happier to pass the torch to such an inspiring leader," Kalanick said.

It is not known how much it cost the company to get Khosrowshahi for the job, but he likely did not come cheap. As the chief executive of Expedia, he was named the highest paid chief executive in the US by Equilar for his 2015 compensation, thanks largely to a long-term stock option package valued at $US90.8 million he would gain access to over a period of several years.

He also had additional options that would be worth another $US82.5 million if aggressive stock price performance targets were met, bringing his total take-home pay to at least $US180 million.

Because Uber is a private company, it won't be required to immediately release specifics on Khosrowshahi's pay, though it would become public if the company launches an IPO.

Bloomberg/The Washington Post