The young adult category is perhaps the hottest market in publishing, so it is no surprise that industry executives are looking for every possible entry point. HarperCollins’s latest effort, to be announced Monday, is a digital imprint focusing on young adult short stories and novellas.

The imprint, called HarperTeen Impulse, will begin sales on Dec. 4 for short fiction in a variety of genres. Although the imprint is open to both new and established authors, it will lean heavily at first on some reliable names.

Its first titles include “Breathless” by Sophie Jordan, described as a companion novella to Ms. Jordan’s popular “Firelight” fantasy series about a dragon in human form, and “Stupid Perfect World,” a futuristic novella by Scott Westerfeld, author of the beloved “Leviathan” trilogy, which mixed alternative history with science fiction.

Impulse says it will make up to four new books available on the first Tuesday of every month through e-book retailers, at prices ranging from 99 cents to $2.99. HarperCollins will back up the Impulse books with dedicated marketing, social media outreach and cross-promotion in HarperTeen print books.

Young adult fiction, which includes blockbuster books like the “Hunger Games” trilogy, has been a bright spot in publishing, an area of strong growth that is attracting not only teenagers but also adult readers. Susan Katz, president and publisher of HarperCollins Children’s Books, said readers of this genre were particularly open to downloading content and reading on electronic screens.

“Readers of Y.A. have embraced digital reading in a big way,” Ms. Katz said. “We’re seeing short-form content becoming more popular in the digital marketplace, and HarperTeen Impulse allows us to experiment with new concepts and deliver content quickly.”