Sometimes, Spam is worth fighting for.

Hormel Foods, based in Austin, Minn., is suing an Ohio firm, alleging it is producing a canned meat product with a logo that’s “confusingly similar” to Spam’s iconic yellow-on-blue design.

The target of Hormel’s federal lawsuit is “Prem,” a competing luncheon meat made in Cincinnati by Netherlands-based Zwanenberg Food Group.

The dispute started in October when, Hormel alleges, Zwanenberg started shipping Prem in the U.S. in packaging similar to Spam’s. In a letter to Zwanenberg last fall, Hormel called it trademark infringement.

Hormel asked the company to stop shipping those Prem products, recall all deliveries and provide an accounting of all its Prem sales. Hormel also asked Zwanenberg to take any offending “Prem” images off the Internet.

Zwanenberg responded that it disagreed with Hormel’s accusations. Regardless, the Cincinnati firm agreed to “amend” the Prem design “for the sake of maintaining good relations.” That appeared to end the dispute.

Hormel and Zwanenberg have had a manufacturing agreement since 2008 that allows Zwanenberg to make luncheon meat on behalf of Hormel. But it agreed not to sell that meat to companies that use packaging that could be confused with Hormel’s, the lawsuit claims.

But a short time later, Hormel discovered Zwanenberg was selling Prem with a “modified yellow-on-blue design” in the Philippines. Prem also is sold in Okinawa, Japan, the lawsuit says.

In another round of letters attached to the lawsuit, Zwanenberg said the modified design on Prem sold overseas differed from the earlier design. “The design of this label was customer-driven,” said Frank Schmitt, Zwanenberg’s general manager, in a January letter to Hormel.

A call to Zwanenberg’s Cincinnati offices wasn’t returned Thursday.

Spam’s legacy runs deep in Austin. Hormel notes in the lawsuit that it has produced 7 billion cans of salty-sweet Spam since 1937.

Millions of dollars have been spent promoting the brand around the globe. Spam has a fan club, a museum in Austin and a spot in the Smithsonian.

In the months to come, it also may have a judge and jury. Hormel’s suit, filed Wednesday in federal court in Minnesota, seeks unspecified damages.