SAN FRANCISCO — Voice-controlled smartwatches that track heart rates and connect to phones and tablets will debut later this year as Google partners with electronics, technology and fashion companies to take consumers to the next promised frontier in computing.

Google on Tuesday unveiled plans to help develop the watches and other wearable computers based on its Android mobile operating system, which runs more than three out of four smartphones sold worldwide.

The Android Wear project is open to software makers to create apps for the watches, putting Google at the forefront of efforts to jump-start the nascent wearable-computing market.

The news comes as speculation swirls around iPhone-maker Apple’s plans for wearable computers, including a smartwatch of its own. Apple chief executive Tim Cook has promised new “product categories” later this year.

By aligning itself with a broad spectrum of partners to develop the smartwatches, Google is hoping to replicate the success that helped make its free Android software the most popular smartphone operating system, analysts said.

LG Electronics said Tuesday that it would introduce its first Android watch, the G Watch, in the second quarter. Motorola said its Moto 360 Android watch would be available this summer. Fossil Group, which makes watches and other accessories, also announced that it was working with Google on Android devices.

Samsung was among the first to sell a smartwatch, but reviewers widely panned its maiden effort, the Galaxy Gear.