Conservative Icon Steps Down

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, according to an internal memo obtained by CNBC on Tuesday.

Koch, 78, and his older brother, Charles, are the key drivers behind a juggernaut political network that has often favored conservative and libertarian politicians and policies, such as tax cuts. His political legacy includes activism in support of free-market initiatives such as eliminating trade barriers between countries and easing regulations on industry.

David Koch, executive vice president at Koch Industries, will become director emeritus.

In the memo to Koch Industries employees, Charles Koch said his brother’s health has continued to deteriorate.