Ralcorp Holdings Inc. again rejected a $5.17 billion takeover bid from ConAgra Foods Inc. and said it won’t negotiate the offer, which likely will put an end to any chance of a deal.

Ralcorp's board previously turned down offers from ConAgra of $82 and $86 a share in April and May. ConAgra raised its bid to the $94 a share in August after Ralcorp proposed to spin off its Post cereals unit and bulk up private label by paying $545 million for the refrigerated-dough business of Sara Lee Corp. (Read more about the deal here.)

St. Louis-based Ralcorp maintains that this plan will "significantly" improve value for its shareholders, according to the board.