Pharrell Williams has filed a lawsuit in the US about his dispute with will.i.am over the 'I Am' branding.

Williams has filed a case in a US court asking them to rule that his 'I Am Other' range does not violate any trademarks owned by the Black Eyed Peas singer.

Apparently, will.i.am has sent letters to Williams asking him to stop using 'I Am' branding on his website, according to lawsuit.

Pharrell's 'I Am' use doesn't feature fullstops between the words and so the star argues that I Am Other does not "infringe, dilute or unfairly compete" with will.i.am's branding.

will.i.am's team are yet to respond.