Digital warehouse and distribution vendor LibreDigital announced yesterday that it received $8.1 million in series C venture capital funding from S3 Ventures, a new LibreDigital investor and early-stage venture capital firm focused on technology. The new investment will be used by LibreDigital to expand its e-book distribution services.

Brian R. Smith, managing director of S3 Ventures, said the investment would help LibreDigital, “speed the delivery of products that help the world’s top publishers and e-reader manufacturers bring the highest quality reading experience to digital consumers.”

The new round of investment also includes participation from existing LibreDigital investors Adams Capital Management and Triangle Peak Partners. Other LibreDigital investors include HarperCollins Publishers, The New York Times Company and Noro-Moseley Partners.

LibreDigital president and CEO Russell P. Reeder said that U.S. e-books sale are expected to double this year to more than $700 million. “This funding will be used to accelerate the delivery of e-books, and expand our technology offerings to include new solutions that help publishers better promote and sell books to digital consumers,” Reeder said.