Heavy metal group Metallica has done a U-turn on its music download policy and has now made all of its songs available for legal downloads on both Apple iTunes and Napster.

Metallica famously sued Napster in 2000 facilitating illegal music sharing online, and demanded that 300,000 file-sharing fans be banned from the site.

The band's albums have been available to download in their entirety from some legal music download sites, but the agreement with Napster and iTunes means that their songs will now be available to download singly.

Vice president of Music Services at Napster, Matt Adell, is quoted as saying, "We think it's great that Metallica has come around and decided to embrace the legal digital distribution platform, and that music fans using Napster can now enjoy this vast and important catalog of music".

Metallica acknowledges the deals have been a long time coming, posting on its website: "From the 'It's about f****** time!' file, comes this … we will begin offering our music on the iTunes Music Store, a Cupertino, CA based upstart outfit, who we feel may very well have a bright future".

At the moment, only iTunes in North America will be offering the tracks; Metallica writes that they didn't want their fans there to have to wait any longer for overseas record companies "to get their s*** together!".

Analysts see Metallica simply bowing to the economic reality that groups have to bow to the demands of music fans for downloads, or risking losing big money.