In the States, has signed a deal to offer Warner Music Group's tunes on its music download service.

Warner Music songs are now available on Amazon "MP3" service, which lets users purchase the tunes and download them, without restrictive digital rights management protection, to a wide range of devices, including iPods.

Warner Music and Amazon also plan to offer exclusive tracks and special album bundles.

Amazon's MP3 service launched in September with DRM-free music from the Universal Music Group and EMI, making Warner the third major label to agree a deal with Amazon, with just Sony BMG holding out.

This makes Amazon's service an even greater competitor to Apple's industry leading iTunes, which only offers DRM-free music from EMI.