"I feel that it is now necessary to leave Rage because our decision-making process has completely failed," de la Rocha said in a statement. "It is no longer meeting the aspirations of all four of us collectively as a band, and from my perspective, has undermined our artistic and political ideal.

"I am extremely proud of our work, both as activists and musicians, as well as indebted and grateful to every person who has expressed solidarity and shared this incredible experience with us."

The band’s label hadn’t prepared a statement regarding de la Rocha’s departure by press time, and there was no immediate word on the future plans of Rage's remaining three members. Besides fronting the band, De La Rocha was also its co-songwriter and lyricist.

Rage Against the Machine experienced a rocky summer. The band planned to co-headline a major tour with Beastie Boys in August and September, but the outing was canceled after the Beasties’ Mike D seriously injured his shoulder in a bicycling accident.

During the Democratic Convention at the Staples Center in Los Angeles this September, Rage Against the Machine performed a concert outside the venue in protest of the two-party system. Though Rage’s set went on without incident, concert-goers and police clashed as the crowd dispersed.

In September, Rage bassist Tim Commerford pled guilty to a charge of disturbing the peace that stemmed from a scene he caused after climbing a stage set during the MTV Video Music Awards ceremony. He spent the night in jail following the incident and was released with time served.

Rage recorded a live album at the Olympic Auditorium in downtown Los Angeles on Sept. 12 and 13. The album is scheduled to be released by Epic Records on Nov. 14.

De la Rocha is expected to pursue a solo career. He and Public Enemy leader Chuck D contributed a cover of the Public Enemy track “Burn Hollywood Burn” to the soundtrack of the new Spike Lee film “Bamboozled,” and he reportedly has been working on a solo album with El-P of Company Flow.

Rage Against the Machine formed in Los Angeles in 1991 and released three albums.

The band is known for using its lyrics and live performances to rally support for various social and political causes, including anti-sweatshop labor campaigns and the movement for democracy in Mexico. Rage has been vocal in its support of Pennsylvania death-row inmate Mumia Abu-Jamal, who the band considers to be a political prisoner.

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