CHICAGO — She's been hailed as one of the most powerful women in business, but in the Midwest, Patricia Woertz is an unknown commodity.

The new chief executive of Archer Daniels Midland Co., the Decatur, Ill.-based agricultural powerhouse, grew up in Pittsburgh but has spent most of her career in California, rising up the ranks of Chevron Corp.

Now she hopes she can turn corn and soybeans into bigger profits, just as she did with oil. It's a big leap for ADM and for the 53-year-old divorced mother of three adult children.

"It would appear that the (ADM) board has concluded it would be easier to teach an energy executive the agricultural side of the business, than an agricultural executive the energy side," Leonard Teitelbaum, a Merill Lynch analyst, said when the company announced the appointment last month.

Woertz is a quick study. An accountant by training, she followed the example of her father, who was the chief financial officer of a large home-construction and development company. Her mother was a librarian and would often take Woertz and her brother on educational vacations.

"My mother felt we'd be earning a living during our entire adult lives, and therefore believed we should spend summers in learning activities," Woertz said in her alumni magazine. "Consequently, I got to see a plate glass factory in Pittsburgh, a U.S. Steel plant and how Heinz made ketchup."

After working for Ernst & Young, Woertz joined Gulf Oil Corp. in 1977 and quickly began climbing the ladder, an anomaly in the male-dominated industry. She is one of three women on the 50-member board of the American Petroleum Institute, the trade organization.

But she has never viewed her gender as a handicap, nor does she think it gave her an edge.

"There is not a job I've held in my career that was held by a woman before me," Woertz said in an interview in 2000. "But if there have been challenges, I never viewed them as a related to gender."

Kenneth Lusht, interim dean at Pennsylvania State University's Smeal College of Business, had an inkling that he was meeting a rising corporate star when Woertz returned to her alma mater to give a speech.

At the reception before the talk, she made a point of walking around and introducing herself to as many people as possible, Lusht recalled. "After she gave the talk, there was another little reception, and, as near as I could tell, she remembered everyone's name. And most, like me, had never met her before," he said. "She's just incredible that way."

She carefully managed her career, taking on extra assignments when asked and being willing to move to gain promotions. In 1993, she was named president of Chevron Canada, taking on her first operating position. That led to jobs as president of Chevron International Oil Co. and later head of its products company.

She started receiving notice as the highest-ranking female executive in the oil industry. Business magazines ranked her among the most prominent women in corporate America.

"I'm sometimes mistaken as the wife of the chairman," Woertz told Money magazine. "I just laugh it off."

In 2001, after Chevron's merger with Texaco, she was promoted to executive vice president of the company's global refining and marketing business. She was in charge of an operation with $100 billion in annual revenue, 19 refineries and 30,000 employees in 180 countries.

Woertz was considered a candidate to eventually become CEO of Chevron, but she abruptly left three months ago without knowing where her next paycheck would come from. She wanted to pursue opportunities to become a CEO, including the job at ADM, and didn't feel like waiting another four or five years.