As part of his softer approach, Mr. Khosrowshahi went on a charm offensive last month in an effort to win over the London transport authorities. Uber is appealing the London ban, which declared the company not “fit and proper” to operate in the city. Uber was allowed to continue operating in the city until a final ruling was made in the case.

Mr. Khosrowshahi’s shift in tone comes at a crucial time. Uber is aiming for an initial public offering in 2019, and working on securing a multibillion-dollar investment from the Japanese conglomerate SoftBank.

As part of its push to win over customers and drivers concerned about Uber’s reputation, the company has introduced new measures and services, including allowing users to add tips to fares. Uber has also promoted its efforts, particularly in Britain, to provide drivers with benefits like access to insurance and pensions.

“Essentially, it has been outrunning employment law and legislators,” said André Spicer, a professor at City University’s Cass Business School in London. “It’s having to become more like a normal company, rather than one that was able to evade existing legal frameworks.”

Uber’s operations in London are crucial to its global expansion. The company started operating in the city in 2012, and now offers its services in dozens of cities nationwide. About 40,000 people drive for Uber in the British capital, and the company says that three million customers have used the app in London at least once in the past three months.

Uber’s arrival in London has, however, set off a clash with the city’s famous black cabs. Drivers in the centuries-old taxi system must pass an exacting test known as the Knowledge, which requires the memorization of around 25,000 streets and 100,000 landmarks. A ride in a black cab is typically far more expensive than using Uber, which cabbies complain is too lightly regulated.

Opponents of Uber argue that it is able to undercut rivals on price largely because of its employment practices, which mean it can avoid paying some of the costs and contributions required by permanent employees. But the company’s business model is facing challenges across Europe. The region’s highest court is expected to rule by year’s end in a case involving whether Uber should be regulated as a taxi service, which would make it subject to rigorous safety and employment rules, or as a digital platform that simply connects independent drivers and passengers.