will.i.am has launched legal action against fellow hip-hop star Pharrell Williams over a branding dispute.

The Black Eyed Peas frontman claims he owns the copyright to the phrase "I Am" and Williams' new creative brand "i am Other" is too "confusingly similar".

In his official notice of opposition, will.i.am states, "The registration of the mark... is likely to dilute the I Am mark and the Will.I.Am mark."

Williams' lawyers have promptly filed a response to refute the allegations, and the Frontin' hitmaker tells Rolling Stone magazine, "I am disappointed that Will, a fellow artist, would file a case against me. I am someone who likes to talk things out and, in fact, I attempted to do just that on many occasions. I am surprised in how this is being handled and I am confident that Will's trademark claims will ultimately be found to be as meritless and ridiculous as I do (sic)."