When Fergie's manager William Derella pitched Wilhelmina Models four years ago on representing his client, agency president Sean Patterson didn't need much convincing.

"We left the first meeting and I said to one of the other agents, 'This girl's completely marketable, every which way,' " Patterson recalls. "She's the hat trick--beautiful, fashionable and cool at the same time. In the beauty/fashion industry, that's gold."

And it has been a golden relationship between Fergie and the 43-year-old agency, which has offices in New York, Los Angeles, Miami and Munich.

Through Wilhelmina, Fergie is one of three musicians to have her own line of footwear with the Brown Shoe Co. (the others are Reba McEntire and Carlos Santana), while her deal with Avon Products started with a fragrance and is now expanding to the company's line of hair care products.

Wilhelmina has also hooked Fergie up with such designers as Dsquared, Calvin Klein and Marchesa, which Patterson says reflects her wide-ranging appeal in the fashion world.

"The cool thing about Fergie as an artist, like any iconic figure in entertainment, is she's constantly evolving," Patterson says. "Fergie is constantly evolving her sense of style. Every six months she looks different. The great artists do that."

Patterson acknowledges that there was some skepticism when Fergie came onboard at Wilhelmina, concurrent with the release of her solo album, 2006's triple-platinum "The Dutchess."

"People in the fashion industry were asking, 'Is she the old Fergie from Wild Orchid? Fergie from Black Eyed Peas, the first couple of albums? Or is she going to be a different permutation in her solo career?' " Patterson recalls. "It was us pointing out to the fashion world she was going to keep evolving, that we already see this in her and if they watch they'll see the same development."

Patterson also praises Fergie as "very collaborative. We'd throw an idea at her and she'd run with it." A case in point is the video for "Clumsy" from "The Dutchess."

"She wanted to do something really fashion-oriented and felt like this would be the moment," Patterson remembers. "I was in Greece, of all places, and Dean and Dan from Dsquared were there at the resort. So I asked them and they flew in for the video along with all these other really cool people from the industry. The second she heard the idea she was like, 'That's it! We're doing that. Let's make it happen.' It was very refreshing to see that she was so collaborative, constantly wanting to evolve herself."

Patterson says the relationships the singer/actress has built with those personalities have helped Wilhelmina create "a Fergie brand" rather than simply spin her toward scattershot projects.

"It's allowed us to build a leverage," he says. "People see her working with Calvin Klein and Dsquared and see how all these unbelievable people in fashion want Fergie sitting at their table and coming to their show and they say, 'We need to buy into this and create a Fergie brand for us, too.' "

Also helping Wilhelmina build the "brand": Fergie is nice, Patterson says.

"She's really, truly one of the kindest, most decent people you're ever going to meet," he says. "For all the titles bestowed on her and all the success she's had, she's completely sweet and kind and . . . so caring about everybody. That's very rare. She almost deserves more praise for how kind a person she is as for being the unbelievable superstar musician she is."

All of that, of course, means Fergie's future with Wilhelmina is bright. Patterson is confident the November 30threlease of the Black Eyed Peas' new album, "The Beginning," will only help.

"Everything the Black Eyed Peas do that helps feed into the success of Fergie as an artist is great for her marketability, of course," he says. "Every deal we're in the midst of negotiating right now, they are light years beyond what those deals would have been three or four years ago."

But don't expect specific details on what those deals are yet.

"Within 12-18 months, you will be very aware of the fact there are more Fergie-branded products coming into the fashion/beauty world," Patterson says. "They'll speak to her fan base and speak to who she is as an artist. She will always be accessible to her fans yet still carry a very cool cachet."