DuPont and activist investor Nelson Peltz are still tussling over the terms of the company's board makeup, the Trian Partners CEO told CNBC on Thursday.
Peltz said DuPont CEO and Chair Ellen Kullman had offered to place one of Trian's nominees on DuPont's board. But Peltz balked.
"I said that didn't work then. It's not working now," he said in a "Squawk on the Street" interview. "I'm willing to have two directors on the DuPont board, me being one of them."
Peltz also wants to place two members on the board of the DuPont spinoff company, Chemours, and said that company's corporate governance must be changed.
"The corporate governance they put out is super-majority voting and a staggered board. We think that's circa 1960. We think the world has changed, and we think we need to change that corporate governance," he said. "That really tells you what the board of DuPoint thinks about all of us as shareholders."
Trian launched a proxy fight with DuPont earlier this year to break up the company's business, a move it sees as unlocking shareholder value. Trian owns $1.9 billion worth of DuPont stock.
He said the governance at DuPont is excellent, and Chemours should have the same model.
DuPont announced in October 2013 it would separate some of the assets and liabilities of its performance chemicals units into a new company called Chemours.
Peltz said he should be on the board because he was in the chemical business at one point in his life and understands it. He further noted that Trian is better equipped to handle the workload and process the research that comes with board membership than the typical director, who has another company to run.