In a Dec. 24 lawsuit filed in the Omaha, Nebraska, federal court, ConAgra said Dean's use on labels of the word "Swiss," a snowy white-and-blue mountain scene, and a particular font are likely to confuse shoppers into believing the teas are endorsed by ConAgra.
Such confusion "is heightened by the similarity in sight and sound of the parties' respective trademarks as well as the fact that the respective products are both marketed in the beverage category," ConAgra said.
The Omaha-based company said it has sold Swiss Miss products since 1990, with sales topping $150 million annually.
Marguerite Copel, a spokeswoman for Dallas-based Dean, did not immediately return a call seeking comment.
ConAgra is seeking to block Dean from using the Swiss Premium label, as well as triple damages and other remedies.
Other ConAgra products include Banquet and Healthy Choice dinners and Orville Redenbacher popcorn.
The case is ConAgra Foods RDM Inc. v. Dean Foods Co, U.S. District Court, District of Nebraska, No. 09-00465. (Reporting by Jonathan Stempel, editing by Dave Zimmerman)