• Silicon Valley shock

Uber Technologies Inc [UBER.UL] Chief Executive Travis Kalanick is likely to take a leave of absence from the troubled ride-hailing company, but no final decision has yet been made, according to a source familiar with the outcome of a Sunday board meeting.

Emil Michael, senior vice president and a close Kalanick ally, has left the company, the source said.

At the Sunday meeting, the company's board adopted a series of recommendations from the law firm of former US Attorney General Eric Holder following a sprawling, multi-month investigation into Uber's culture and practices, according to a board representative.

Uber will tell employees about the recommendations on Tuesday, said the representative, who declined to be identified.

The company is also adding a new independent director, Nestle executive and Alibaba board member Wan Ling Martello, a company spokesman said.

Holder and his law firm were retained by Uber in February to investigate company practices after former Uber engineer Susan Fowler published a blog post detailing what she described as sexual harassment and a lack of a suitable response by senior managers.

The recommendations in Holder's firm's report place greater controls on spending, human resources and other areas where executives led by Kalanick have had a surprising amount of autonomy for a company with more than 12,000 employees, sources familiar with the matter said.

Kalanick and two allies on the board have voting control of the company. Kalanick's forceful personality and enormous success with Uber to date, as well as his super-voting shares, have won him broad deference in the boardroom, according to the people familiar with the deliberations.

Any decision to take a leave of absence will ultimately be Kalanick's, one source said.

The world's most valuable venture-backed private company has found itself at a crossroads as its rough-and-tumble approach to local regulations and handling employees and drivers has led to a series of problems.

It is facing a criminal probe by the US Department of Justice over its use of a software tool that helped its drivers evade local transportation regulators, sources have told Reuters.

Last week, Uber said it fired 20 staff after another law firm looked into 215 cases encompassing complaints of sexual harassment, discrimination, unprofessional behaviour, bullying and other employee claims.

Silicon Valley shock

Even a temporary departure by Kalanick would be a shock for the Silicon Valley startup world, where company founders in recent years have enjoyed more autonomy and often become synonymous with their firms.

Uber's image, culture and practices have been largely defined by Kalanick's brash approach, company insiders and investors previously told Reuters.

Uber board member Arianna Huffington said in March that Kalanick needed to change his leadership style from that of a "scrappy entrepreneur" to be more like a "leader of a major global company."

The board has been looking for a chief operating officer to help Kalanick run the company since March.

The debate over Kalanick's future comes as he is also facing a personal trauma: His mother died last month in a boating accident, in which his father was also badly injured.

Michael, described by employees as Kalanick's closest deputy, has been a recurring flashpoint for controversy at the company.

He once discussed hiring private investigators to probe the personal lives of reporters writing stories faulting the company. Kalanick disavowed and publicly criticized the comments.

Michael will be replaced as the company's top business development executive by David Richter, currently an Uber vice president, the company spokesman said.

Alongside Uber's management crisis, its self-driving car program is in jeopardy after a lawsuit from Alphabet Inc alleging trade secrets theft, and the company has suffered an exodus of top executives.

One Uber investor called the board's decisions on Sunday a step in the right direction, giving Uber an "opportunity to reboot."