Microsoft Corp  has introduced three new models of its Zune digital media player that wirelessly and automatically update their music, photos and videos when placed near a user’s computer.

They mark the second generation of Microsoft’s answer to Apple Inc’s iPod, which has sold more than 100 million units in various shapes and sizes since its 2001 launch.

By comparison, Microsoft joined the fray last year with a single 30-gigabyte Zune model and has sold 1.2 million units.

The new Zunes will come in 4-gigabyte, 8-gigabyte and 80-gigabyte models. All will come with a feature that allows a user to automatically sync media via a WiFi network from a PC to the Zune when its battery is charging.

Microsoft also aims to tap the social-networking phenomenon with Zune Social, a website for users to display music they like, share playlists and find friends with similar tastes.

The new devices, set to go on sale in mid-November, are equipped with a circular navigational pad that allows a user to both “flick” through options like on a touch-screen or “click” through choices.

The 4-GB model will go on sale at $149, the 8-GB Zune will cost $199 and the 80-GB model will sell for $249. Those prices are the same as similar-sized iPods.

Analysts said the next-generation Zunes are necessary to keep existing users happy, though the new devices are not enough to close the gap on Apple.

“I don’t see Microsoft gaining market share on Apple, but it may gain share against the other also-rans,” said Van Baker, analyst at research firm Gartner, noting SanDisk Corp and Creative Technology Ltd  may be vulnerable.

Microsoft’s top brass plans to provide Zune with a three-to four-year window to gain the necessary scale and reach to become a legitimate rival to Apple. The company has also said it does not expect Zune to post a profit in the short term.