Woertz, who will succeed G. Allen Andreas, has extensive experience in the oil industry, suggesting that the ingredients giant plans to further diversify into this field.
She was most recently executive vice president of Chevron Corporation, in charge of the oil company's 'downstream' operations, including refining, marketing, lubricant, supply and trading businesses in 180 countries, with more than $100 billion in annual revenues and a global workforce of 30,000. Woertz was one of the highest-ranking executives in the energy industry.
"Pat Woertz is a proven executive with an exceptional blend of strategic, analytic, business and leadership skills," said Andreas.
"Her selection was endorsed unanimously by our Board of Directors, and we are confident that she is the ideal person to sustain ADM's strong performance and lead the Company into the next chapter of its history."
Woertz becomes only the 8th CEO in the 104-year history of ADM. Her appointment also makes ADM the largest publicly traded company, based on revenue, to have a female CEO.
Fortune magazine has named Woertz one of the top ten most powerful women in business every year since 2000.
"I am honored and excited to be part of the ADM organization and look forward to working with its outstanding leadership team and board of directors," said Woertz.
"ADM is one of the leading agricultural companies in the world, with a long tradition of applying innovation and resourcefulness to feed and fuel the world. While most of my executive experience has been in the field of energy, there are considerable similarities in commodity-based businesses as we build competitive advantages across the value chain."
Prior to becoming executive vice president at Chevron in 2001, Woertz was president of Chevron Products since November 1998. In January 1996, she was named president of Chevron International Oil and a vice president of logistics and trading for Chevron Products.
In October 1993, she was named president of Chevron Canada, a refining and marketing company and a wholly-owned subsidiary of Chevron Corp.
ADM is one of the world's largest processors of cocoa, soybeans, corn and wheat, as well as a leader in the production of soybean oil and meal, ethanol, corn sweeteners and flour. The company, which owns over 250 processing plants, last year reported net sales of $35.9 billion.
Sales for the company's second quarter this financial year, ending 31 December 2005, were $9.3 billion, an increase of three per cent compared to the same period in 2004. Second quarter operating profit increased to $524 million (€435m), a rise of eight per cent.
Management said the results from the quarter reflected the company's strategic use of its worldwide network to expand its food and industrial markets.
The company releases its third quarter results later today.