OMAHA, NEBRASKA, U.S. — ConAgra Foods Inc. on Sept. 13 said it plans to withdraw its approximately $5.18 billion offer for St. Louis, Missouri, U.S.-based Ralcorp Holdings, Inc. by Sept. 19 if the company doesn’t “engage in a constructive dialogue.”

ConAgra has sent Ralcorp a presentation on the merits of its $94-a-share bid, but so far Ralcorp, the maker of Post cereals, has rejected three offers from ConAgra, the latest coming in August. Earlier, Ralcorp shunned bids of $86 per share and $82 per share.

Instead, Ralcorp has said it plans to spin off its Post Foods unit to focus on making private label foods.