The site is a "lifestyle boutique" for contemporary, trendy styles within Bluefly.com, company officials told WWD on Tuesday.
B*fly will carry separates for women and men, including graphic tees, colorful tunics, casual denim, Boho dresses and accessories, and seek to cater to a younger audience.
"B*fly is designed to be that coveted specialty boutique that every fashionista strives to find," Bluefly president Melissa Payner said. "We recognize that our shoppers are not always wearing head-to-toe haute couture, so now they have an outlet where they can find the hottest contemporary separates and mix and match trends to create their own signature look."
Bluefly.com says it sells over 350 American and European designers starting at 40 percent off.
The site was founded in 1998 and is listed on NASDAQ.