Tennant Co. said Friday that it has dropped its appeal of a German court ruling over allegedly misleading ads about its hot-selling, chemical-free floor cleaners.

The Golden Valley-based company let stand a June 2013 decision in favor of competitor Alfred Karcher GmbH & Co. KG. The German court ordered Tennant to change the language of its ads. Tennant had appealed.

Tennant said it decided to redirect legal costs associated with the case toward "innovation" and launching more environmentally friendly products.

Tennant maintained that the German court was wrong.

"The withdrawal [of the appeal] is for purely commercial reasons as the case was primarily about advertising claims that are no longer being used by Tennant," General Counsel Heidi Wilson said in a statement.

The dust-up over Tennant's cleaning machines came after it launched an environmentally friendly line of floor "scrubber-dryers" in 2008. Tennant, with $734 million in annual revenue, said the machine did not use chemicals. Instead, officials said, the scrubber used a solution and electrical charges to turn water into an effective cleaning detergent that protected the environment and saved users money. Sales took off and reached roughly $140 million last year.

Karcher has long insisted that Tennant's advertising claims were misleading and that they should be banned by the court. It took Tennant to court in Germany and filed a complaint in England with the U.K. Trading Standards Service. Other rivals also challenged Tennant's claims.

Last year, Karcher lost its case before the U.K. Trading Standards Service. But in June, it won a favorable ruling in the German court.

Tennant's stock closed Friday at $61.09, up $2.21 a share.