Fidelity Investments is competing to lead Uber Technologies Inc.’s new financing in a round that could value the ride-sharing service at about $17 billion, according to people familiar with the situation.

Other investors are jostling to put money into the San Francisco-based startup and the terms of the funding might change, said the people, who asked not to be identified because the talks aren’t public.

Uber’s new financing, if completed at a $17 billion valuation, would mean the company is more valuable than public companies including car-rental service Hertz Global Holdings Inc. and retailer Best Buy Co. Other closely held technology startups such as Dropbox Inc. and Airbnb Inc. have raised money at a $10 billion valuation in recent months.

Representatives for Uber and Boston-based Fidelity either declined to comment or didn’t return a call for comment.

Uber Chief Executive Officer Travis Kalanick said last week that the car-service booking application could fetch a “record breaking” valuation with its funding.

Bloomberg News reported last month that Uber, which has rolled out its service in 115 cities globally, is in talks with new private-equity investors to raise less than $1 billion at a valuation topping $10 billion. Uber is garnering new financing to boost growth and expand its operations, people with knowledge of the matter have said.

Fidelity has become an active investor in closely held technology startups, along with other mutual fund firms including T. Rowe Price.

Startup Fervor

The fervor around startup financing has renewed debate about whether Silicon Valley is in a new bubble. While there are fewer technology IPOs today than in the late 1990s dot-com boom, venture funding hit $10 billion in the first quarter, the most since 2001, according to researcher CB Insights. Startup financing rounds in the first quarter also reached their highest median valuation increase since 2004, according to a survey by law firm Fenwick & West.

Uber was founded by Kalanick and Garrett Camp in 2009 after they couldn’t find a cab during a trip to Paris. The company has raised $307.5 million from investors including Benchmark, Menlo Ventures, TPG Capital and Google Ventures.

Uber has a high-end service for limousines and luxury cars, as well as lower-priced options. The company, which has 900 employees and takes a 20 percent commission from its drivers, recently started a courier service in Manhattan that may be expanded elsewhere.