It's been four and a half years since Tupac Shakur was murdered, yet that hasn't slowed down the rapper's output. "Until The End Of Time," a double-CD of previously unreleased recordings due out March

It's been four and a half years since Tupac Shakur was murdered, yet that hasn't slowed down the rapper's output. "Until The End Of Time," a double-CD of previously unreleased recordings due out March 27, will be the first of two Shakur double albums to be released in 2001.

The Interscope/Death Row/Amaru album features material that was recorded during Shakur's final year. A Death Row spokesperson confirmed that the more than 20 tracks would be all new recordings, noting that none of the songs are reworkings of older Shakur numbers, though the songs have been "touched up."

The spokesperson added that the album would feature at least one guest rapper, Death Row recording artist Crooked I, who will appear on the track "Untouchable." Additional tracks on the album include "Last One Left," "All Out," "Mama's Just A Little Girl, "Happy Home," "Let Em Have It," and "Thug N U Thug N Me."

The album was executive produced by imprisoned Death Row founder Suge Knight and Shakur's mother, Afeni, who started Amaru Records to put out her son's unreleased catalog. The second, as-yet-untitled double album will be released before the end of the year, but the label could not confirm whether or not it will also consist of all new material.

"Until the End of Time" will be the fifth posthumous Shakur album -- or sixth, counting 1998's "Greatest Hits" collection -- to dig through the vaults.

The rapper's final year was mined once before on "Don Killuminati: The 7 Day Theory," released about two months after Shakur died in September 1996. Though the Death Row album was met with a lukewarm reception, it went on to sell more than 3 million copies in the U.S., according to SoundScan. Along with the flurry of recording, the rapper also found time in 1996 to star in "Bullet" and "Gridlock'd."

Shortly after the release of "Don Killuminati," Afeni acquired the rights to her son's unreleased material. The 1997 Jive/Amaru release "Are You Still Down (Remember Me)?" collected material recorded during the sessions for Shakur's first three albums and peaked at No. 2 on The Billboard 200.

The last album of unreleased Shakur songs, 1999's "Still I Rise" (Death Row/Interscope/Amaru), suggested that the catalog was thinning out, as the group the Outlawz were called in to fill in the unrecorded gaps in songs. Still, the album spent 20 weeks on The Billboard 200, peaking at No. 6, and selling about 1.3 million copies.

Last winter, Interscope/Amaru released "The Rose that Grew From Concrete Volume 1," a collection of Shakur's poetry, which has moved about 121,000 copies.