DuPont chief Ellen Kuhlman will retire later this month, the chemical company said Monday as it also cut its earnings forecast for 2015.
Kuhlman, 59, DuPont chief executive and chairman, will exit on October 16, according to a post-market announcement that caught market watchers by surprise.
DuPont board member Edward Breen will serve as interim chief executive while an executive recruitment firm searches for a successor to Kuhlman, a 27-year DuPont veteran.
"We thank Ellen for her extraordinary leadership as chair and CEO of DuPont," said DuPont lead independent director Alexander Cutler.
"As our chair and CEO, Ellen led DuPont through the global recession and the dramatic transformation of the last several years with the highest standard of integrity and commitment."
In May, Kuhlman, 59, successfully fought back a challenge from shareholder activist Nelson Peltz, who had sought four board seats on the 213-year-old company that produces insecticides, enzymes for food production and a variety of specialty chemical products.
Peltz had also advocated a breakup of the company.
Peltz's firm Trian Fund Management holds 2.7 percent of DuPont and had pledged to "closely monitor DuPont's performance" following the bruising campaign.
Peltz had criticized DuPont under Kuhlman for repeatedly missing earnings forecasts, undertaking poorly conceived acquisitions and divestitures and not aligning bloated executive pay with performance.
DuPont had argued that it was already reforming itself, returning billions of dollars to shareholders, restructuring the company's holdings and positioning itself to capitalize on its research advances in chemicals and agriculture technology.
On Monday, DuPont also slashed its full-year earnings forecast to about $2.75 per share from the prior $3.10 estimate. The company cited the strengthening of the US dollar, as well as poor demand for crop protection and seed products, especially in Brazil.
Dow member DuPont jumped 5.4 percent to $54.04 in after-hours trade.