"Women basically said, 'I'm not wearing tight jeans I'm done with them,' " he said.
One convert is Luciana Mando, 29, a New York stylist, who prefers to "dress in a relaxed way."
Another is Stacey Kontoh, 34, a medical technician from New York. She already owns a few pairs of loosely cut palazzo pants and loves the professional and dressy look.
Busy women want clothes they can wear to yoga and work, said Nancy Green, Athleta's general manager.
"Women don't want to change five times a day," she said.
After years of squeezing themselves into skinny jeans, many women are ready for comfort, said Wendy Liebmann, who runs WSL Strategic Retail, a New York-based research firm.
The "trend fits the size of the American shopper," she said. "It is much more forgiving for most or many women."
For the past several years, women have been snapping up athletic apparel from Lululemon Athletica and Gap's sporty Athleta brand. Exhibit A: Lululemon's stretchy, $108 Studio Pant II, a loose-fitting garment designed to get women to and from the yoga studio. Last year, dressier versions of the athletic look began showing up on the runway in a range of fabrics from linen to cotton to silk. Gap's latest styles include zippered sweats and capri track pants.
New fashion trends, when they catch on, have a multiplier effect because women are forced to buy new shoes, blouses, jackets and so on. That's what happened with skinny jeans, when women began buying a lot of boots, including Uggs, because they could fit their jeans inside them.
By pushing looser-fitting pants, retailers are hoping they can persuade women to replace existing tops with more structured and fitted blouses that work with the look. This year Bloomingdale's has been carrying coordinated blouse-and-pants combos for customers uncomfortable with mixing and matching. Gap also is using displays as teaching props.
While women's apparel sales rose 1 percent to $116.2 billion in the U.S. in the 12 months ending in June, sales of women's pants grew twice as fast to $8.2 billion, according to NPD, which is based in New York. Looser fitting styles are largely responsible, Cohen said.
Retailers could use a lift. Wal-Mart Stores, Target and Macy's all reported disappointing results this month. The Commerce Department's report on July retail sales was the weakest in six months, hurt by tepid wage growth.
The big question is whether women are really ready to move on from skinny jeans, a garment whose staying power in recent years has confounded many fashion watchers.
The look originated in the 1950s when the likes of Gene Autry squeezed into them. Mick Jagger and the Rolling Stones reprised skinny trousers in the early 1960s. Hippies responded with flares and bell-bottoms until the Sex Pistols and the Ramones made sprayed-on denim de rigeur for suburban punks.
The look re-emerged in the 1990s, when women's magazines began looking more to the boyishly slim Kate Moss than curvy Cindy Crawford. Skinnies, leggings and jeggings (leggings that look like jeans) showed up from Manhattan to Minneapolis.
More recently, denim sales have slipped, hurting retailers unwilling to adapt to new trends, said Betty Chen, an analyst at Mizuho Securities USA in San Francisco.
While a craze for colored denim temporarily lifted the business, that trend's "newness" has evaporated, she said.
"Until we see another big fashion innovation around denim, we could see it languish around these levels or continue to be sideways in terms of sales," Chen said.
The loose fit will be a hard sell with some women. Gina Girodier, who works in television and film production in New York, said the look doesn't work with her figure.
"My shape is wide at the top and I have skinny legs," said Girodier, 29. "So whenever I wear wide legged pants it just looks really weird."