SAN FRANCISCO >> Google is unveiling a small tablet computer bearing its brand.

Called the Nexus Seven, the tablet will have a screen that measures 7 inches diagonally, smaller than the nearly 10 inches on Apple Inc.’s popular iPad. That means it’s more likely to challenge Amazon.com Inc.’s Kindle Fire, which is also 7 inches.

The Nexus Seven will also be light — at about 0.75 pound, compared with the Kindle Fire’s 0.9 pound. The iPad weighs 1.44 pounds.

The device will ship in mid-July starting at $199 — the same price as the Kindle Fire. By contrast, iPads start at $499. Customers can start ordering it through Google on Wednesday, initially in the U.S., Canada and Australia.

The Nexus Seven will run the next version of Google Inc.’s Android operating system, called Jelly Bean. The tablet is also designed specifically for Google Play, the company’s online store for movies, music, games, books and apps. Google said Wednesday that Google Play will now offer movies for sale, rather than only rentals.

Google also announced a home entertainment device called Nexus Q. It sends content from your personal collection or YouTube to your existing TV and speaker systems. You control it through a separate Android phone or tablet.

A Google expansion into the tablet market brings another imposing entrant into what is already a battle of tech heavyweights. Last week, Microsoft Corp. announced its own tablet, Surface. Expected to go on sale this fall, Surface will run on a revamped version of Windows and compete directly with the iPad.