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Google parent Alphabet Inc. is pushing into the rapidly expanding ride-sharing business with a new app that lets commuters carpool together, further fraying its ties with Uber Technologies Inc.

Alphabet on Monday unveiled a pilot program that will enable several thousand San Francisco-area workers to hitch rides to or from work with users of Alphabet's popular Waze navigation app. Riders will pay drivers 54 cents a mile, and Alphabet won't take a cut during the pilot.

The program signals Alphabet is likely to use Waze as a way into the increasingly popular world of ride sharing, pitting it more directly against Uber, the world's most valuable private venture-capital-backed company, which dominates ride sharing in the U.S.

Alphabet and Uber have been allies. Alphabet's Google Ventures invested $250 million in Uber in 2013 and included prompts to book Uber rides in its Google Maps app. Alphabet's senior vice president for corporate development, David Drummond, is on Uber's board.

However, the relationship is increasingly fraught. Uber is developing its own mapping and driverless-car technology, which could compete with Alphabet's efforts to develop a self-driving car. A spokeswoman for Uber declined to comment on the company's relationship with Alphabet.

The new ride-sharing program comes just days after Apple Inc. invested $1 billion in Chinese ride-sharing firm Didi Chuxing Technology Co., whose other investors include Chinese Internet giants Alibaba Group Holding Ltd. and Tencent Holdings Ltd. General Motors Co., meanwhile, invested $500 million in Uber rival Lyft Inc. Many of the companies are also hoping to upend transportation by pairing their bets on ride sharing with work on driverless cars.

Alphabet said it began testing its carpooling app, called Waze Rider, in Tel Aviv in July 2015. Thousands of people now use the app across Israel, where Alphabet takes a 15% commission on each ride. In the fall, Google employees began testing the app and their use will expand under the new pilot.

An Alphabet spokeswoman said the company doesn't have long-term plans for the app and is simply testing it to gauge users' interest. She also said that unlike Uber or Lyft, drivers won't be able to make a living off Waze Rider because they are limited to two rides a day—to and from work. Drivers will be paired with only one rider and they will have to share near identical commutes.

Riders in the pilot are limited to about 25,000 Bay Area employees of several companies, including Wal-Mart Stores Inc. and Adobe Systems Inc., but Alphabet expects only a fraction of those workers to use the service. Alphabet said that over the next several weeks it will gradually offer the opportunity to drive for the carpool service to several thousand of the more than 700,000 Waze users in the Bay Area. Alphabet said it doesn't plan to vet drivers for the carpooling service, which has been an area of controversy for Uber and Lyft.

Douglas MacMillan contributed to this article.

Write to Jack Nicas at jack.nicas@wsj.com

(END) Dow Jones Newswires

May 16, 2016 16:35 ET (20:35 GMT)

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