Calvin Klein to begin selling new underwear only through Amazon

New styles to be available through online retailer and pop-up shops through the holiday season

Calvin Klein is for the first time selling new underwear only on Inc. AMZN -0.89% this holiday season, bypassing the department stores that typically have first dibs on its latest styles.

The move signals a deepening of the decade-old relationship between Amazon and Calvin Klein, which is owned by PVH Corp., and shows how brands are looking for new ways to reach shoppers as they visit department stores and other traditional retailers less frequently.

A model in Paris wearing a Calvin Klein design last June

Calvin Klein was among the first brands to embrace Amazon by selling a limited selection of products, mainly underwear and jeans, through the online retailer. As Amazon has grown, more labels have followed suit, including Nike Inc., Tapestry Inc.’s Kate Spade and Levi Strauss & Co., overcoming concerns about pricing, presentation and the prospect of working with a potential rival.

“We want to reach consumers wherever they are shopping,” said Cheryl Abel-Hodges, president of PVH’s underwear group. “Digital is one of our fastest-growing channels, and Amazon is a really important part of what is happening in digital.”

Amazon is now the biggest U.S. apparel seller, according to Cowen & Co., and it continues to gain market share. It has launched numerous private-label brands and earlier this year introduced Prime Wardrobe, a service its Prime members can use to order clothes and return what they don’t want after seven days. Customers are only charged for what they keep and receive a discount on those purchases.

“Fashion is one of our fastest-growing categories, and we are always looking for new ways” to appeal to shoppers, said Michelle Rothman, Amazon’s vice president of fashion.

Calvin Klein’s decision to offer some products only on Amazon during the important holiday shopping season is a setback for department stores, which have been losing share to online retailers and discount chains. Department stores are the main distributors of Calvin Klein underwear and jeans in the U.S., since the brand doesn’t have its own full-price retail stores selling those items here.

The new Calvin Klein underwear styles, including cotton bralettes and striped panties, will be available on Amazon through a dedicated Calvin Klein page and in pop-up shops in New York and Los Angeles from Thursday through Dec. 31. Department stores won’t receive the styles until January.

Customers who visit the pop-up shops can purchase items through Amazon’s mobile app. The dressing rooms will feature Amazon Echo devices that can answer questions about the merchandise, control the lighting and play music. Shoppers at the pop-up stores will be able to customize their purchases with embroidery.

The Calvin Klein page on Amazon will include products the brand has already sold through the site, as well as the new exclusive styles.

A model in Paris wearing a Calvin Klein design last June