To take on iPhone, Microsoft builds on Zune

Microsoft’s mobile system powered 13 percent of smartphones sold in the United States last year, according to the research firm In-Stat. That made it number three, after Research In Motion Ltd.’s BlackBerry and the iPhone. But Microsoft has been losing market share while Apple and Google Inc.’s Android gained.

All the while, the market is becoming increasingly important. People are spending more time on their phones, and the devices steer people to potentially lucrative Web services and ads.

Phones with Microsoft’s new software will be on the market by the holidays, the company said. All four major US carriers will offer phones, just as they sell current Windows phones.

The new ones won’t be called Zune phones, as had been speculated. The software will be called Windows Phone 7 Series.

A Forrester Research analyst, Charles Golvin, said the new software looks promising, but it’s Microsoft’s “final chance to get it right.’’ He noted that those who have current Windows phones don’t seem excited about the brand.

Andy Lees, a senior vice president at Microsoft, said Windows Mobile suffered from the company’s chaotic approach to the market. The software maker gave phone hardware makers and wireless carriers so much freedom to alter the system and install it on so many different devices that none worked the same way.

Other phone vendors linked their hardware and software tightly to ensure a better experience.

With the new software, “We really wanted to lead and take much more complete accountability than we had in earlier versions of the Windows phone for the end user experience,’’ chief executive Steve Ballmer said at the Barcelona launch event.

Microsoft is imposing a set of required features for Windows phones. Manufacturers must include permanent buttons on the phone for “home,’’ “search’’ and “back’’; a high-resolution screen with the same touch-sensing technology as the iPhone’s; and a camera with at least 5 megapixels of resolution and a flash. Hardware QWERTY keyboards will be optional.

A test device from Asus, which Microsoft used to demonstrate the new phone software for the Associated Press in Redmond, Wash., also had a front camera and a speaker.