Ralcorp, the spinoff several years ago from Ralston-Purina, is under buyout attack from ConAgra. Ralcorp’s board has rejected a second hostile takeover offer, this time for $4.9 billion dollars.

Ralcorp, based in St. Louis, owns Post foods and last year picked up American Italian Pasta.

If the two companies do get together, they’d become the nation’s third-biggest packaged foods company.