Koch Industries has supplanted Cargill Inc. as the largest private company in the U.S. for the first time in 13 years.

It’s only the third time in Forbes’ 35-year history of ranking U.S. private companies that Minnetonka-based Cargill wasn’t the largest.

Forbes ranks companies by their annual sales and the gap between Koch and Cargill is relatively narrow — just $400 million.

Koch Industries, a Wichita, Kan.-based conglomerate with interests in energy, chemicals and many other industries, had an estimated revenue of $115 billion in 2019, representing a 4.5% growth over the previous year. Cargill reported fiscal year 2020 revenue of $114.6 billion, an increase of $1.1 billion over the year prior.

Cargill, as one of the world’s largest food and agriculture companies, faced a series of challenges last year, including the U.S.-China trade war, African swine fever and — to top it all off — a pandemic that affected its 155,000-person global workforce in various ways.

“This was a year that tested all assumptions: about how markets and supply chains function in an age of global interdependency; about what it means to truly deliver for customers, consumers and communities; and about how companies can and should operate in a crisis,” Dave MacLennan, Cargill’s chief executive, said in the company’s annual report.

Koch has a sizable presence in Minnesota. It owns the Flint Hills Pine Bend Refinery in Rosemount, the state’s largest refinery.

Cargill debuted at the No. 1 spot with revenue of $30 billion in 1985 when Forbes began publishing a list of private companies.

The private-company list is a bit squishier than public-company rankings. Revenue figures are pulled from voluntary disclosures, Securities and Exchange Commission filings — which are required in instances of publicly traded debt — and estimates from Forbes researchers and outside sources.

There’s only one Minnesota company larger than Cargill: publicly traded UnitedHealth Group with revenue at $242.12 billion.

According to Cargill, it reinvests on average 80% of its operating cash flow back into the company.