Nicola Formichetti has joined Diesel as artistic director.

The designer - who announced his departure from Thierry Mugler earlier this week - has been chosen by the brand's founder Renzo Rosso to oversee the denim company's international development.

Renzo told WWD: ''I finally met somebody as crazy as I am. I have replaced myself and can go on vacation.

''I have to spend my time running the [OTB] group and really can't go back. Nicola is here to develop Diesel, the most important part of the group.''

He added that Nicola would be in a charge of ''a total view of the Diesel brand - product, communications, marketing and interior design. I want him to do bigger things, different things.

''This is the right man to take the next step for a young company and a brand for people who are young of mind.''

An official announcement is expected to be made today. Nicola is said to be focusing on making a move from ''high fashion and couture to streetwear and activewear'' and his new ideas will be implemented within the next five to 10 years.

The 35-year-old Italian designer - best known for his work as Lady GaGa's stylist - claims he has always been a fan of the pioneering denim company since his days as an 18-year-old student in London.

He explained: ''I didn't have the money to buy in those days, but their stores were the place to be. They did great parties and shows and spoke to an audience that was into music and art.

''They did ads with guys kissing. It was very anti-fashion and very appealing to me.''

This comes after rumours began circulating yesterday (03.04.13) that Nicola would be partnering with Diesel after he said he ''wanted to do something else, even bigger, more global'' after his two-year tenure at Mugler.