Billionaire conservative donor David Koch to retire from Koch Industries

10:03 AM ET Tue, 5 June 2018

Billionaire industrialist, donor and political activist David Koch will retire from his roles at Koch Industries and other Koch-affiliated groups due to health reasons. Koch was diagnosed with prostate cancer more than two decades ago. "His guidance and loyalty, especially in our most troubled times, has been unwavering," Charles Koch wrote in an internal Koch Industries memo obtained by CNBC.