Google is set to introduce a subscription music feature to compete against fast-growing streaming services like Spotify, according to several people briefed on its plans.

Google is planning to introduce the new service as early as Wednesday at Google I/O, the company’s annual conference for software developers. The subscription feature will be connected to Play, Google’s online media hub, complementing its download store and “locker” feature, which lets people store their digital entertainment collections online, according to these people, who spoke on the condition of anonymity before Google’s official announcement.

News of the announcement first appeared on The Verge, a technology-oriented website. A Google spokeswoman declined to comment.

Google has been developing entertainment features for Android mobile devices, which puts the company in direct competition with digital music leaders like Apple, whose iTunes store is the largest retailer of music — digital or physical — in the United States. While Android phones and other devices remain extremely popular, Google has had limited success with its download store, people in the music business say.

By expanding to streaming music, Google will be tapping into the most rapid growth area in digital music. Spotify, which was founded in Sweden in 2008 and came to the United States almost two years ago, now has more than 24 million regular users, 6 million of whom pay about $5 to $10 a month for premium service. Pandora now has more than 200 million users, the vast majority of whom use it free.

Apple is also said to be developing a Pandora-like Internet radio service, although its negotiations with record labels and publishers have been slow.

Google’s streaming service will not include a free tier, according to the people briefed on the plans.