Paul Frank puts a damper on Julius's party

Eponymous designer quits monkey business on 10th birthday of his primate creation

Just as his most famous creation - Julius the monkey - celebrates his 10th birthday, the designer Paul Frank, has resigned from the company that bears his name.

Paul Frank Sunich, to give him his full name, quit last week, giving no reason for his departure. The company will continue to be run by its two co-founders, John Oswald and Ryan Heuser. In a statement, Paul Frank Industries said that the 38-year-old Mr Sunich would remain "a significant stakeholder".

His departure comes at an embarrassing time for the company. On Friday it celebrated the 10th anniversary of Julius the monkey, the cartoon character that is featured on many of Paul Frank's products. These have proved particularly popular among girls and young woman.

Mr Sunich, from Huntington Beach, California, came up with the design when he was an art student trying to make cheap, waterproof wallets to sell to surfers.

It took two years for the products to catch on among a wider market and, with investments from the other two partners, Paul Frank Industries was created in 1997. The company later expanded into clothing, backpacks and accessories. It now boasts more than $40m (£23m) of turnover and a total of 14 stores including branches in London, Tokyo and Seoul. As well as Julius, the company's animal characters now include a giraffe called Clancy and Ellie the elephant.

If Paul Frank Industries continues to thrive, it will join the likes of Jil Sander, Helmut Lang and Roland Mouret as fashion companies that have carried on after their eponymous founder has left.