Rockers R.E.M. have released remastered versions of their entire back catalogue of hits, album tracks and rarities as part of a new iTunes package for fans to download.

The disbanded group has made versions of its I.R.S. studio albums, Warner Bros. albums, and two rarities collections available to fans online, three years after splitting up.

The band's Complete I.R.S. Studio Albums package is comprised of six studio albums, including R.E.M.'s debut EP Chronic Town and the critically acclaimed albums Murmur, Reckoning and Fables of The Reconstruction.

The Complete Warner Bros. Studio Albums, Vol. 1 package features the five hit albums the band released between 1988 and 2011, and Complete Rarities - I.R.S. 1982-1987 includes 25 hard-to-find tracks, including B-sides, soundtrack material and cover versions of tunes like Roger Miller's King of the Road and the Velvet Underground's Pale Blue Eyes.

The Complete Rarities - Warner Bros. 1988-2011 package features 131 tracks that span more than two decades. Highlights include non-album tracks, live performances from legendary U.K. festival Glastonbury and U.S. comedy show Saturday Night Live, and covers of songs by Syd Barrett and Leonard Cohen.

The new iTunes packages also include R.E.M.'s Unplugged performances from 1991 and 2001, featuring 11 songs that never aired on MTV.