The chemical maker said on Thursday that it would replace two of its existing directors with people of its own choosing, after what it said was a rebuffed attempt to settle a fight with Mr. Peltz’s hedge fund, Trian Fund Management.
DuPont will add Edward D. Breen, the chairman of Tyco, and James L. Gallogly, a former chief executive of the chemical maker LyondellBasell. The two men will replace Curtis J. Crawford and Richard H. Brown, who will eventually become directors of Chemours, a manufacturer of performance chemicals that the company plans to spin off later this year.
In a regulatory filing, DuPont said that it approached Mr. Peltz — who last month began a campaign to win four seats on the chemical maker’s board — about reaching a settlement. Although the company had picked two of its own nominees, it was willing to take on one of Trian’s candidates as well in exchange for a cease-fire.
But Mr. Peltz refused when told that he would not be joining the board, according to the filing.
In a statement late Thursday, Trian said the appointment of the directors was a “positive development,” saying that Mr. Breen and Mr. Gallogly have “records of stockholder value creation.”
But it also indicated that a proxy battle was looming, saying that “we cannot be passive while management continues to falter.”
“While DuPont frames Trian’s insistence that Nelson Peltz be added to the board as a negative, we believe fellow stockholders want our nominees on the board, specifically Mr. Peltz,” Trian said.
The move on Thursday escalates the battle between the 213-year-old corporation formally known as E. I. du Pont de Nemours & Company and Trian. The fight stretches back to the fall of 2013, when Mr. Peltz first disclosed that he owned a stake and began agitating for change at the manufacturer both publicly and privately.
It is only the second time that Trian has waged a proxy fight for director seats. The first, at H.J. Heinz, ended with Mr. Peltz winning two seats on the ketchup maker’s board.
At the center of Trian’s critique is that DuPont suffers from a combination of bloated bureaucracy, poor management and chronic underperformance. The company has countered by arguing that its stock has beaten major indexes and that it has taken steps to improve returns for shareholders.