Sony BMG will soon offer its music catalogue DRM-free on iTunes, reports suggest.

Apple rumour site 9to5Mac states on a "hunch" that the Sony record label will offer its tracks in the iTunes Plus format in the next few weeks.

iTunes Plus is Apple's way of describing higher quality audio tracks without any copy protection, a format which Apple first launched back in May 2007.

Although Apple is the largest retailer of music online, it has not managed to secure DRM-free tracks from all the major labels, unlike Amazon who currently offers DRM-free digital downloads from all four majors.

In the UK, and 7digital offer DRM-free downloads from the four major labels.