Wal-Mart is to sell free of DRM-free MP3s on its website, which means tracks should play on competing multimedia players such as the iPod and Microsoft's Zune.

Wal-Mart will continue to sell songs in Windows Media Audio, Microsoft's proprietary format. That format will be cheaper, at $0.88 per track, but encoded at 128Kbps. MP3s will be better quality, at 256Kbps.

Pricing for the higher-quality MP3s will be US$0.94 per track or $9.22 per album, Wal-Mart said. Music will come from major labels including Universal Music Group and EMI Group, with artists including The Rolling Stones and Coldplay, Wal-Mart said.