RBmedia, one of the largest independent publishers and distributors of audiobooks, has been acquired by yet another private equity firm. Monday morning KKR announced that it had bought the company from Shamrock Capital. Financial details of the transaction were not disclosed.

Shamrock acquired RB Media—then known as Recorded Books—in August 2015, after losing out in its bid to acquire the company to Wasserstein & Co. in January 2014. Under Shamrock, Recorded Books was renamed RB Media in May 2017, the same day it acquired Audiobooks.com.

RBmedia now has a catalogue of more than 35,000 audio titles spanning all genres–-from romance to business to sci-fi—and continues to add to its list. In addition to distributing audio directly through Audiobooks.com, its RBDigital cloud-based digital media platform provides audiobooks to libraries and library patrons

Citing the proliferation of mobile devices and voice-enabled ecosystems has growth drivers for digital audio, Richard Sarnoff, one-time Random House executive who is now chairman of Media, Entertainment, and Education for KKR, said in a statement he is certain more growth for RB media lies ahead. “This trend has made audiobooks the most growth segment of the publishing industry. RBmedia is very well positioned to capitalize on these dynamics with the industry’s largest independent catalogue of premier audio content that can be flexibly delivered across platforms, worldwide.”