Google is taking its fight with Apple to the wristwatch. The search giant has unveiled Android Wear, a version of Google’s Android operating system software that is tailored specifically for wearable computers, starting with so-called smartwatches.

Adjusting Android - a breakaway hit as an operating system for smartphones - to work with wearable computers is a pre-emptive move for Google, which entered the smartphone and tablet markets after Apple.

This time, it should have a first claim on developing relationships with the many software partners - the apps builders - that help a gadget become popular. Just as important, consumers should expect to see Android-powered smartwatches before Apple can get into the mix.

Apple has been developing a watch for some time, according to people briefed on the project, but it is not clear when it will be released. “They’re trying to get in front of whatever Apple is going to do,” said Tero Kuittinen, a telecom analyst for the mobile diagnostics firm Alekstra.

For several years, Google and Apple have been waging what analysts call a war of ecosystems: apps, content and services used to lure customers and keep them loyal. The better the apps and content, the more appealing their devices get. Apple’s strategy has been to build gadgets based on its own software and then allow outside developers to make apps for a huge audience of iPhone and iPad customers.

Google’s approach has been to team up with manufacturers that build devices aroundGoogle-made software, which the other companies install free. In the process, the potential market for products based on the Google software is widened.

Google’s Android is by far the most popular operating system for smartphones, but developers of some of the biggest apps, like Instagram, still tend to build for Apple’s iOS first and Android second.

Developers have said they work on iOS first because it is easier to develop an app for Apple devices than it is to make apps for the many kinds of Android devices on the market. Android phone manufacturers use the same basic software, but many of them have made small changes that can make app developers’ work more difficult.

Google is clearly trying to change that for wearable computers by making its software public before the market takes off. “It’s important that Google is getting its ducks in a row to be able to offer a new outlet for Android developers, and it’s something that Apple will want to do when it launches into the wearables space, too,” said Jan Dawson, an independent telecom analyst for Jackdaw Research.

That is, if Apple does indeed produce what some have named the iWatch. While numerous sources as well as tech news outlets have reported that Apple is working on a smartwatch, the company has never stated that it has one in development or said when it would be released. But if - or when - it does release such a product, it will be entering what some believe is the next big market for tech gadgets.

Though wearable computers have yet to gain traction among mainstream consumers, they are expected to become popular in coming years. Companies like Samsung Electronics, Sony and Pebble are already making smartwatches. The research firm Gartner estimates that wearable devices, including shoes, tattoos and accessories, will be a $10 billion market by 2016. One of the first smartwatches running the Google software will be the LG G Watch from LG Electronics, the South Korean electronics maker.

Another, the Moto 360, will come from Motorola Mobility, the handset maker that Google recently agreed to sell to Lenovo.

Google said it was also working on watches with Asus, HTC and Samsung.

Google collaborated closely with LG on the design and the engineering of the G Watch, according to Jong-seok Park, chief executive of LG’s mobile communications division. LG said that after users say to its watch, “OK Google,” followed by a voice command, the screen will present relevant information.

That is similar to the voice-controlled system used for navigating Google Glass, the Internet-connected monocle, and Moto X, the smartphone that Motorola developed for Google.

The new Android software for wearable gadgets was opened to app developers on Tuesday.

More information will most likely be shared in June at Google I/O, the company’s annual conference for software developers. Google would not comment on whether manufacturers would have to pay a licensing fee to use Android Wear. Christopher Katsaros, a Google spokesman, said more details would be announced in the coming months. It was unclear whether Google would eventually make its own watch.

But the company has shown a strong interest in hardware, despite a spotty track record. Google Glass, which has been an object of envy among some gadget enthusiasts and the subject of derision among others, is not yet in wide production. And the more successful Google-branded Android devices weren’t made by Google itself, but by partners like Samsung Electronics and LG.

Google’s biggest splash in hardware came in 2012, when it bought Motorola Mobility, the handset maker, for more than $12 billion. But in January, after sales of Moto X, Google’s first flagship smartphone, were disappointing, Google said it would sell Motorola to Lenovo, the Chinese company, for about $3 billion.

Weeks before Google announced that sale, it said it would buy Nest, a hardware company that makes Internet-connected thermostats, for $3.2 billion. By relying on other hardware makers to make a smartwatch, one thing beyondGoogle’s control is the physical design.

That could be an issue, since some people complain that smartwatches are ugly. “They’re just not that attractive,” said Dawson, the telecom analyst. “And they are all clunky, square and large.”