Did you buy that Tiffany engagement ring along with six large cans of cling peaches the last time you made a run to Costco?

Well, a Manhattan federal judge said pretrial evidence has established that Costco, the largest US warehouse club chain, had infringed Tiffany’s trademarks by selling engagement rings — and that it confused consumers by using the word Tiffany in display case signs.

Manhattan federal court Judge Laura Taylor Swain rejected Costco claims that Tiffany’s trademarks were invalid because they sought to prevent others from using the word Tiffany as a generic description of a type of ring setting.

“Despite Costco’s arguments to the contrary, the court finds that, based on the record evidence, no rational finder of fact could conclude that Costco acted in good faith in adopting the Tiffany mark,” Swain wrote.

Under the terms of the judge’s ruling, Tiffany may now take Costco before a jury to seek damages. These penalties could include a recovery of Costco’s profits from the sale of the diamond rings, as well as punitive damages.

Swain set a hearing for Oct. 30 and directed Tiffany and Costco to “make good faith efforts to settle the outstanding issues.”

In a statement, Tiffany General Counsel Leigh Harlan welcomed the ruling, saying it “further validates the strength and value of the Tiffany mark and reinforces our continuing efforts to protect the brand.”

Representatives for Costco did not respond to requests for comment.

Tiffany filed the lawsuit on Valentine’s Day in February 2013, saying it believed hundreds, if not thousands, of Costco members bought engagement rings they wrongly believed were authentic Tiffany products.

With Post Wires