Melissa Cohlmia, a spokeswoman for Koch Industries, confirmed the company’s revenue and declined to comment on the brothers’ net worth in an e-mail.
Their company agreed to buy printing-ink maker Flint Group Holdings Sarl for about 2 billion euros ($2.8 billion) last week. Flint, one of the world’s largest ink suppliers to the printing and packaging industry, is being bought with Goldman Sachs Group Inc.’s private-equity unit from CVC Capital Partners Ltd. The billionaires also own Atlanta-based Georgia-Pacific LLC, which makes Dixie cups, Brawny paper towels and Quilted Northern toilet tissue.
Elaine T. Marshall, 71, holds almost 15 percent of Koch Industries. She is the planet’s fifth-richest woman and has a net worth of $17.3 billion, according to the Bloomberg ranking. She gained control of the Koch stake following the death of her husband, E. Pierce Marshall, in 2006.
Bill Gates remains the world’s wealthiest person, controlling a $79.5 billion fortune. He is followed by Mexico’s Carlos Slim, who has a net worth of $67.1 billion, and Berkshire Hathaway Inc.’s Warren Buffett, whose wealth is valued at $64.5 billion.
The Bloomberg Billionaires Index takes measure of the world’s wealthiest people based on market and economic changes and Bloomberg News reporting. Each net worth figure is updated every business day at 5:30 p.m. in New York and listed in U.S. dollars.