ST. LOUIS: Fleishman-Hillard is providing media relations services to Ralcorp Holdings in its acquisition of Post cereals. Fleishman has worked with Ralcorp periodically in the past. The current merger is an all-stock transaction valued at about $2.6 billion including debt issuance and assumption. Post cereals has a century-old history and includes ready-to-eat cereals such as Honey Bunches of Oats, Grape Nuts, and Post Raisin Bran. Among Ralcorp's other store brands are Bremner and Carriage House.