Apple has spurned Microsoft's attempts to make the latter firm's future online music store iPod-compatible, reports Rolling Stone.

The magazine claims that Microsoft will "roll out its own music store on September 2". The report points out that Microsoft may be able to send 350 million users each month to its store through Hotmail, Messenger and MSN, predicting the firm will become the number two legal music service, and "could challenge Apple".

"Sources close to Microsoft, the store will open to the public with somewhere between 600,000 and 700,000 tracks for sale at 99-cents apiece," Rolling Stone says.

Speculation also exists that Microsoft will use its vast financial muscle to pay The Beatles to carry their catalogue online, the report says, adding that the firm may bundle its music store with future versions of Windows.