iPod chip designer PortalPlayer filed for its initial public stock offering on August 4.

The company says it hopes to raise $75 million (£41m) but market watchers note that PortalPlayer is not a profitable company.

The company lost $8m last year and another $3.3m in the first half of 2004. But, notes CNN: "Losses have narrowed during the past few years. PortalPlayer lost $25.3 million in 2001 and $22.5 million in 2002."

The company said it was reliant on Apple for 85 per cent of its revenues last year and clearly owes much to the success of the iPod. PortalPlayer has reported that sales in the first six months of 2004 have already topped last year's total revenues of $21m.

While some analysts suggest that the dominance of the iPod may not continue once competitors such as Microsoft and Sony enter the digital-music scene, there may be life in the iPod yet. PortalPlayer newest chip, the PP5020, is the first to feature photo-processing capabilities, in addition to audio. That could spell a camera or video version of the iPod – or at least enable iPod users to view the photos they are able to store on the device.