Hearst Magazines Digital Media has purchased an online social and dating network for teens and young adults, and says it’s planning to launch a new teen-centered Web site later this month, as well as unveil new Web sites for its three teen magazines next month.

Hearst has purchased a network of several youth-oriented Web sites operated by eCrush.com Inc. The sites include eCrush.com, a site in which users can find out anonymously if someone they have a “crush” on feels the same about them. Launched on Valentine’s Day 1999, the site has matched more than 900,000 and has more than 2.4 registered users. Terms of the deal were not disclosed.

The eCrush network also includes eSpin-the-Bottle.com, a profile-based site that allows the Gen-Y set to connect, flirt and make friends online; and HighSchoolStyleBoard, a photo-rating site that allows users to post photos in different categories such as “best hair” and displays a Top 500 list for the highest vote getters.

Later this month, Hearst will launch interactive, prom-planning destination, MyPromShopper.com. Next month, it will relaunch new Web sites for CosmoGIRL.com, Seventeen.com, and Teenmag.com. Each new magazine will feature a unique design, as well as interactive content, photos, video and podcasts. The company plans to relaunch other sites later in the year as it rolls out its digital strategy.