Ozzy Osbourne [ tickets ] has filed suit against guitarist Tony Iommi over ownership of the Black Sabbath [ tickets ] name. The trademark-infringement suit--which, in part, claims Osbourne's signature lead vocals are largely responsible for the band's extraordinary success--was filed Friday (5/29) in a New York federal court, and reportedly seeks to return ownership of the name, as well as profits from the use of the band's name and logos, to the original four Sabbath members, Osbourne, Iommi, Geezer Butler and Bill Ward.

The quartet formed Black Sabbath in the late 1960s. Ozzy was fired in 1979--reportedly due to his excessive drinking and drug use--and replaced by former Rainbow vocalist Ronnie James Dio.

Iommi--without Osbourne--performed under the Black Sabbath moniker until the late 1990s and, according to Ozzy, destroyed the value of the band's name. "After constant and numerous changes in band members, the brand of 'Black Sabbath' was literally in the toilet," Osbourne said in a statement.

"Since 1997 when Geezer, Bill and myself rejoined the band, Black Sabbath has returned to its former glory as we headlined sold-out arenas and amphitheatres playing to upwards of 50,000 people at each show around the world," Osbourne said. "We worked collectively to restore credibility and bring dignity back to the name 'Black Sabbath' which lead to the band being inducted into the UK and US Rock & Roll Hall of Fames in 2005 and 2006, respectively. ... The name 'Black Sabbath' now has a worldwide prestige and merchandising value that it would not have had by continuing on the road it was on prior to the 1997 reunion tour."

Osbourne said the quality of the Black Sabbath brand has increased significantly with the help of his management representatives (comprised primarily of his wife, Sharon Osbourne) who oversaw the marketing and quality control of the brand through Ozzfest, touring, merchandising and album reissues.

"It is with great regret that I had to resort to legal action against my long term partner ... but after three years of trying to resolve this issue amicably, I feel I have no other recourse," Osbourne said. "I don't have the right to speak for Geezer and Bill, but I feel that morally and ethically the trademark should be owned by the four of us equally. ... We've all worked too hard and long in our careers to allow you to sell merchandise that features all of our faces, old Black Sabbath album covers and band logos, and then you tell us that you own the copyright."

Iommi reportedly registered the "Black Sabbath" trademark in the US in 2000 and has been the only Sabbath member to stay with the band throughout its 41 year history. The guitarist and founding member--who now tours under the " Heaven and Hell [ tickets ]" moniker with original Ozzy replacement vocalist Dio--reportedly has filed his own suit against Signatures Network for selling merchandise with the band's likeness, name and logo.