Trian Fund Management, headed by Nelson Peltz, has amassed a "big stake" in chemicals maker DuPont, CNBC said on Wednesday.

Shares of DuPont rose 4.8% on the news of Trian's stake. At the CNBC Institutional Investor Delivering Alpha Conference, Peltz declined to comment in response to questions by CNBC host Andrew Ross Sorkin on his DuPont interest.

DuPont declined to a Reuters request for comment. "We don't comment on market rumors or speculation," DuPont spokesman Michael Hanretta said.

Investors have agitated for months about the company's low stock price compared with rivals Monsanto and BASF. While DuPont is the second-largest seed maker after Monsanto, its stock trades at a large discount to its rival.

DuPont's titanium dioxide paint business, the largest in the world, has been blamed by some investors as weighing on the stock. The business is highly cyclical and requires large infusions of cash to maintain during troughs.