NEW YORK (AdAge.com) -- Hearst Magazines is shutting down CosmoGirl magazine after its December issue, the company confirmed this morning. Its subscribers will receive issues of Seventeen instead; its brand will continue at CosmoGirl.com.

CosmoGirl, the Cosmo spinoff introduced in 1999, follows Time Inc.'s Teen People and Hachette's ElleGirl out of print. Ad pages in the first three quarters came in 14.4% lower than in the same period last year, according to Media Industry Newsletter. Circulation slipped 1.4% in the first half but sank 18% on newsstands, where advertisers often look for signs of a magazine's vitality, according to reports filed with the Audit Bureau of Circulations.

"This was a very difficult decision, and I want to extend my personal appreciation to Editor in Chief Susan Schulz, who joined CosmoGirl shortly after its launch, nearly a decade ago, and has been its editor for the past five years," said Cathie Black, president of Hearst Magazines, in an internal e-mail this morning. "She is a highly talented editor and will continue to work with us on a special-projects basis."

Vicki Wellington, CosmoGirl's publisher, is being named publisher of Hearst's new Food Network magazine.