One of the world's richest men, Adelson is donating $10 million to the campaign activities of the billionaire Koch brothers. A person familiar with Adelson's pledge confirmed the donation Friday, requesting anonymity to discuss the private arrangement.
Adelson has already contributed $10 million to a super political action committee that backs likely Republican presidential candidate Mitt Romney, Restore Our Future, and $5 million to each of two organizations promoting House Republicans.
During the GOP presidential primary, Adelson and members of his family gave $21 million to a super PAC promoting former House Speaker Newt Gingrich.
Oil executives Charles and David Koch founded small-government, anti-tax group Americans for Prosperity.
