Ralston Purina completed the sale of Foodmaker.

The St. Louis-based firm and Gibbons, Green, van Amerongen announced that they have completed the sale of Foodmaker Inc., the restaurant subsidiary that operates the Jack in the Box chain, for about $450 million. The purchaser was a holding company owned by institutional investors, including partnerships managed by Gibbons, Green and members of Foodmaker’s senior management. Ralston Purina will own 20% of the holding company.