Two huge companies finally locked horns in the music player market in 2006 as Microsoft launched its long-awaited Zune player in November. 

However, the attack on Apple's domination of the music market with its massive iPod sales and successful iTunes download service faces an uphill struggle, according to industry experts. 

Ovum analyst Carl Gressum said that the lack of a worldwide release showed the battle Microsoft was facing to eat into Apple's lead. 

"This is not Microsoft's first attempt at the portable entertainment market; the soon-to-be-extinct PlayForSure springs to mind," he said. 

"Microsoft lacks a distribution partner for digital music in Europe, and has therefore not introduced the Zune in Europe for the time being. It is also not present in Asia."

Gressum said that the Zune also has other disadvantages, such as competing with the 3,000 accessories that are available for the iPod, and cutting deals with companies such as airlines and car manufacturers which are willing to integrate either iPods or iPod docking stations into their designs.

Barring the imminent launch of a wireless iPod, the Zune's big selling point is the ability to share music using a Wi-Fi connection. Unfortunately, Gressum said that even this had limitations.

"It only works for three days, or the music can be played three times, whichever occurs first. Microsoft will face an uphill battle against Apple and its wider range of products," he said.