DuPont has rejected a request from activist investor Nelson Peltz and his hedge fund Trian to use a universal ballot in an upcoming vote on candidates for the chemical producer's board of directors.

Trian has launched a proxy fight to take four of the seats on DuPont's 13-member board.

A universal ballot would put both Trian's four nominees and DuPont's full 13-member board on the same document sent to shareholders, rather than each side sending its own version.

While the traditional proxy process uses white cards containing the company-backed nominees or gold cards that list the shareholder nominees, the universal proxy allows shareholders to split their vote if they are not fully convinced of either party during a proxy battle.

"DuPont is forcing stockholders to elect either the Trian slate of candidates or the DuPont slate of candidates, rather than permitting stockholders to elect whichever candidates they prefer," Nelson Peltz said in a statement.

"We believe it would be inappropriate for a company with the size of our shareholder base to serve as a test case, especially as the matter at hand is so critical to the value of our shareholders' investment," DuPont said in a letter sent to Trian, pointing to concerns about its large base of retail investors.

With market capitalization of $71 billion, the chemical producer is one of the largest firms to be engaged in a proxy fight. Compatriot Dow Chemical sidestepped a fight with its own activist investor, Daniel Loeb and his Third Point hedge fund, through a last-minute compromise agreement.

A universal proxy could compromise access and accuracy and issuing the card to all 600,000 individual shareholders could be cumbersome, the chemical group added.

The universal ballot is said to have played a key role in two failed proxy fights of billionaire activist investor William Ackman, who recently also lost a battle for control over Botox manufacturer Allergan.

DuPont has yet to set a date for its annual meeting, but it is usually held in late April.